Showing posts with label portable radio. Show all posts
Showing posts with label portable radio. Show all posts

Friday, February 2, 2024

Lunchtime Ham Radio Shenanigans


Antenna over the edge

 Today (2024-02-02) on my lunch break,  I managed a QSO with Vern (NJ8L) in Newark, OH! Our QSO with each other count is up to three! The first 2 times look like SKCC contest QSOs on 40m. He confirmed both of those with me, so I look forward to the new band confirmation. 


Happy Face Due to Great QSO

Here's The scoop: while contemplating participation in the yearly FYBO event this weekend,  I decided to go ahead and bring a radio to work to test my setup.  I used my QCX+ on 20m running about 3 watts. During my lunch break, I set up in about five minutes, and called CQ, an EFHW (End Fed Half Wave) antenna carrying RF into the ether. The antenna I used might be this one: EFHW Part 3 Bigger is Better? It certainly is at least the same design RF wise.

I did receive some spots, but not a lot. I also tuned a little bit, and heard NJ8P calling CQ at 14.061 MHz. I answered and we conversated for a couple minutes before I returned to my desk. Tomorrow, I might just make it outside to Freeze my Buns off. 


I'll be seein' you on the air!




Monday, April 18, 2016

What do you Call Ham Radio Shenanigans?

Shehamigans!
Doesn't really roll off of the tongue.
Hamnanigans!
Something, I don't really like that either.
Anywho, I did get up to some ham radio shenanigans recently, notably on Sunday March 12th during the WES (Weekend Sprint-a-Thon). The family went to the beach, and I brought my SW-20, and a vertical antenna I've been working on. I didn't figure I'd get much time to do radio, that's why this fits in the category of "shenanigans". I had two goals:
1. Set up in less than 10 minutes.
2. Make one QSO.

Anything else would be gravy.

Antenna is Up
Radio Deployed
I had some trouble with the first goal. I would get a wire stretched out, and then have to chase down a kid. All said, we were there about an hour before I was fully set up. I probably spent just over ten minutes of that setting up. My biggest issue came when I undid everything. I had to spend most of my time untangling the radiator from the radials. I remember this problem last time I set this pole up, and remembered that my solution was to wrap the radials up first, and then the radiator, so that the radiator could be deployed without undoing the radials.Everything should have taken under 5 minutes to set up. After setting up, I tuned around where I thought the WES would be taking place, and I was rewarded with signals! That's a plus! Throwing the antenna tuner into tune mode, and twiddling knobs for maximum noise, I quickly discovered that tuning this antenna in this configuration is not easy. I don't know if it's the twists around the pole, or interaction due to proximity to the radio, but it would not tune well at all. I've tuned this before at the house, but not with the center conductor spiralled around the support pole. Some more trimming may be needed for the wire. I tuned around until I heard the loudest signal I could, and tried to call him when I had a chance. It was Bill in TX, K8DN/5, and his fist sounded great. After two tries, I managed to get Bill to copy my call, and give me a 339, but he couldn't hear me complete the exchange. That was ALMOST a QSO. QRN was just too great, plus my transmitting situation was suboptimal. Still glad I had the practice. After tuning around a couple more minutes, I shut the station down, the kids were needing me, so time to stop being a sun baked ham, and time to start being dad at the beach.



The whole experience goes to show that perfect practice makes perfect, and I've not been practicing enough. Perhaps some mini-trips to the outdoors after school one day? IDK, Most of the time I'm too busy to bother fooling with radio, but I might start trying to set up. Maybe during lunch I can pop out to the car, set up, call CQ long enough to be heard on a reverse beacon net, then pop back in. I carry the stuff in the car now just in case.


Thursday, November 19, 2015

Work Parking Lot Portable

Tonight was the NAQCC Sprint, and I decided to attempt participation from the parking lot at work.
I didn't get any QSOs, didn't even manage to get out to the vehicle until after 10:15, but I did hear stations, and I called CQ NA a few times even.


This time, I reinforced an idea I've had in my head a while. If your antenna isn't set up in 5 mins, your risking time wasted. Next portable system will be like that. It may or may not involve a collapsable fishing pole. The other day I tried to set up my SLV in the parking lot, and the pole kept collapsing. I've been rethinking the SLV concept, and might make some modifications in the future. Last night I used my EFHW antenna. I didn't have a way to measure SWR, but every other time I've checked it out, it has been excellent!
I didn't make any calls, but I copied some fairly strong signals, and did manage to capture some spots on the Reverse Beacon Net.
Next time I'll try harder!

 All of these reports were sent from my SW-40 aka "The Killer Watt Radio"
I need a freqmite...
Not bad over all though, for a radio that was putting out less than 1.5 watts!



Tuesday, June 3, 2014

Definately Spartan, but a Sprint?

Whelp,
managed to QRV on 20m for the June Spartan Sprint.
I can hardly believe it!

KG4GVL is QRV!


Working nights is a pain for a lot of reasons, there's stress of not being home when my kids are  home, the stress of not being available for social activities, no time for radio when everyone else is doing things like sprints, or nets. There's stuff during the day too, and I do QRV when I can, but there's not the Spartan Sprints, or NAQCC sprints. There's pluses too, like how I don't have to send my kids to daycare, and the pay is good, and the company I work for is a good company to work for, I'm just looking for the sweetspot where I can have my cake, and eat it too.

Enough bellyaching, let's talk SP!

I took a lot of gear for this operation, too much really, I wanted to use my St Louis Vertical, and when I got to work, I realized that I was missing the jumper that goes from my tuner to my radio. Fortunately, I brought a couple of end fed antennas, and since I wanted to try 20m (20 had been good to me during the WPX contest at night), I decided to put up the homebrew end fed for 20m.
Setup went well, and baring any production issues, I eagerly awaited an opportunity to clock out for "electric lunch".

Close to 21:30 local time (01:30 UTC) I realized that production issues would prevent me from taking a full lunch, but that I needed a break, so I took 10 minutes to go outside for an "electric coffee break". I turned the SW-20 on, spun the dial, and best guessed where 14.060 is. I've got it pretty well pegged on this radio, and it wasn't long before I heard one VERY STRONG signal on 14MHz. It was W3KC, in MD running 5w! The end fed was mostly oriented on a slant, with the bottom end in the North West, and the top end in the South East. The far end was bent over a tree branch, so I don't know how I managed it, other than the antenna was mostly straight, ran to a fairly decent height, and had about a 30 degree pitch or so.
That was the only contact I managed. I did hear some TX station, WA5??? but couldn't grab him, QRN is fierce in the work parking lot.
I went back inside happy to make one QSO.
73,
GB Hoyt

Sunday, May 25, 2014

7276


Yep,
More numbers.
Ham radio club members are obsessed with trading numbers with each other. Every club has numbers it seems, even some of the ones of who don't have dues or officers!
0
here's some of mine:
QRPARCI (the first number I ever got) 10774
Flying Pigs: 2359
SKCC: 6161
4SQRP: 473
SOUTHCARS: 10360
QRP-L Zombie: 1059

and most recently:

the NAQCC : 7276, the number featured as the title of this blog.

On Wednesday night, May 21 (22 May 0200 UTC) I decided to get a lil QRV in an effort to practice my rapid radio deployment skills.
Here's a short video I made when I got to work:




I moved the vehicle once the parking lot cleared out some, and stretched my antenna up and across the parking lot. It was about 6 inches higher than my upstretched hand at the middle. 10-15 feet at the highest. Not exactly the best placement, but I know from experience that this height will get me a good match on 40m, so a tuner isn't necessary.  There's a decent number of QRP operators between FL and GA so I figured someone would hear me if I could hear them.

When I'm at work, I don't really have much time to operate. I get a 15 minute break and a 30 minute lunch break. During my 15min break, I worked like mad to get the antenna fully deployed, and then started calling CQ just to see if I could get a reverse beacon spot, and figure out where in the band I was transmitting. Lo and behold, after the second round of calling CQ, I get a station come back to me! It was Jim, W3GYM, just down the road in "The Villages" FL. We had a short QSO, then I had to head back inside to work.

I copied Jim! W3GYM.




About forty five minutes after my QSO with Jim, things at the work front slowed down enough so that I felt comfortable clocking out and taking a "lunch break". The action began when I plugged the radio in, and tuned up and down the band.

Knowing where you are with "The Killer Watt Radio" is an exercise is best-guestimation. I know that at the bottom of the tuning range, I'm around 7005 KHz, and the top, 7070KHz. I had plans on building a freq mite, still might, but not sure if I want to do that, or just do something with a digital display. I go back and forth. Probably should do a freq mite. When Dave retired the Small Wonder Labs business, he gave the design to the 4SQRP club and they gave me a number, so I should support them.

I tuned up the band, trying to guess where 7030 was, and then down the band, trying to guess the same. Finally, a lound "CQ NA" came on the air, and I worked K4BAI. He's not a stranger in my log, and it is always a pleasure to work him. I tuned around a little more, and heard some more CQ's, but QSB and QRN fought to keep me from catching the whole call. Finally, I copied N5GW, and added DX to the log. Hey, when your antenna is between 8 and 15 feet off the ground, outside of your home call area is DX! I tried to call CQ NA on a clear frequency between these two FB OP, but no luck, only two contacts for me. I took the antenna down and packed up my station when I clocked out to go home that night.

key on my leg, gettin' 'er done!

The important thing about this little excursion was not that I scored well, or that I have a new antenna to share about, or even that I now have all kinds of nice numbers to trade with other people. Happily I got on the air, and made some contacts. Didn't need to make many, just needed to have one.
Mission accomplished.
Now to find another club I can join who will give me a number that I can trade...


Sunday, May 18, 2014

40m is Open

Missed the Four Days in May again, but at least I played radio today some, may even it the band up again.
40m is open!
Started at about 9:30, worked a fella in North Carolina.
(BTW, did the run fer the bacon get cancelled? I missed the memo.)
then, turned on the dx, worked a couple that I've worked before, Peter HA8RM, and  Mauro I1MMR.
Setup is non-standard at the moment. I'm inside the house, running a line out the door, to my end fed half wave antenna. Still need to get out the W3EDP and string it up...
maybe Saturday at work.
Rig I'm running is "The Killer Watt Radio", it's an SW-40 in a custom aluminium case (I butchered something up from Radio Shack the way I wanted to), and a 10 turn pot.
I also modded the bandspread so that it would cover 7.005 to about 7.070 MHz, I can tell you that's about as far as the bandpass filter will take it. I get about 80% max power on the edges of the band because the bandpass filter wasn't designed for a 65KHz spread.
Rig is also battery powered inside, using some 7AH SLA I got from a guy on QRP-L
so yeah,
Ham radio wise, things are looking up!
Life is good.

Sunday, December 8, 2013

December WES Adventures

Plenty of Murphy on this adventure.
Where to start...
I got to work about 15 minutes early, and attempted to deploy my End Fed Half Wave antenna. After throwing the antenna into the tree over an acceptable, but not optimal, branch I started to hoist it into place. The antenna hung up about 3/4 of the way to being fully deployed and the support line broke. Because I had to get on the clock, I stopped, and waited until my first 15minute break to finish deploying the antenna. Getting the antenna in the air was easy enough but I discovered more trouble when I tried to tune in a signal.
First, I noticed the antenna was quieter than normal. This could be explained by solar conditions. I was still receiving signals, the band was just less noisy. Then I transmitted, and the SWR was way off. I inspected the line and the transformer. When I looked into the pillbottle holding the transformer, I was in for a shock.

He Broke!
I had to rush it in for emergency surgery.

It can be fixed!

I cut the bottle open, and used a lighter to get the solder hot enough to flow and reconnect the antenna connection.

After sealing everything back up with duct tape, I reinstalled the antenna, and made a total of four QSOs. Here's the video account of my WES adventures.
Please don't forget to like the video and share it with your friends!
73,
GB Hoyt

Saturday, November 23, 2013

It's True, Ham Radio Always Gets Through

Wednesday, 20-Nov-2013 I pulled one of the craziest ham radio stunts I've ever pulled.
It started when my oldest two kids brought home a sheet of paper that said  something about "The Great American Teach-in." My wife suggested I talk about ham radio.

I accepted, and found myself agreeing to speak to two classes, one full of kindergardeners, and one full of third graders. When I speak to kids, I can't help but smile. They ask questions, tell you stories, and keep you thinking all the time.

I decided pretty quickly on two things:

1. QSL cards would have to be involved. They are a good, quick visual way to show something about ham radio.
2. It's one thing to tell people about amateur radio, but I wanted to go further. I knew that somehow we would have to find a way to do radio.

With this in mind, I concocted a plan to spend about five to ten minutes talking about radio, and the balance of the time trying to make a QSO. I decided to bring several radios, so the kids could see what a built radio looked like, and so that they could understand that making radios is an important part of the hobby (to me). I used my Swan 100MX to attempt contacts because I wanted the power the Swan transmits (100w max). I brought several antennas, and two different ones, one for the kindergardeners, and a different one for the third graders. I did this because I had the ability to set my station up before hand with the kindergardeners, and I had to do the set up "live" with the third graders.

The setup for the Kindergarden class went smooth. Earlier in the week I had my two daughters help me build an antenna, the 2 band HF Groundplane featured in December 2013's QST. They were great help getting it made, and I wanted them to be able to generate some chatter about helping build it after I gave the presentation. I used this antenna for the Kindergardeners. A parent volunteer from the school helped me get things set up. He was a great help, and it turns out his third grader is in my third grader's class, so that was cool. Testing it out, I had some hiccups in connecting the feedline to the antenna, but it shook out after I reseated the connection. I went to get some juice on the air, and discovered three unfortunate things right away. First of all, my phone's battery was depleted. I think it's getting old. Certainly, it doesn't hold a charge like it use to, and it cut off at the absolute worse possible time. Second, the update that happend to the twitter application on my phone broke the application 15 minutes before I needed the application to announce my operating times/frequencies. Third, once I did manage to get my weakened battery to power on, I discovered that the clock was out of sync, and that instead of being several minutes early, I was late. I hate being late. Kids couldn't tell I was that late though. Propagation was strange on 15 and 20, and we made no contacts. Kids still gawked at the antenna and radios though, so that was pretty neat.

Shortly before my scheduled appearance time with the third graders, I tore the station down, packed it up, and trucked it over, making it just in time.
I walked into the class room with RG-8 wrapped around my chest like a bandolleer, and said:
"My name is Mr. Brandon, and I'm here to tell you about the greatest hobby in the world, Amateur radio."
Apparently, I made a great impression, because my daughter relayed later how some of the guys said I was "cool".
We went outside, and I passed out the QSL cards, I had them find the names and locations of the hams on the cards, while I got the station laid out. Then I spent about 10 minutes quizzing the kids about the information they discovered on the cards, and telling where each one originated, and the QSO that went along with it. I then told them how radios take one kind of electricity and turned it into another, and I plugged in the powersupply, and turned the radio on. We didn't hear much, because I hadn't hooked the antenna up yet. I hooked up the antenna tuner, and we still heard nothing. Then I hooked up the antenna. When I turned the radio on, I had strategically placed the dial near the lower end of 20m hoping to hear some CW. That strategy worked. They heard Morse Code. I was using a different antenna this time, for the third graders I wanted to use and easy to deploy antenna, one with a single support. I chose one of the End Fed Half Wave antennas I recently described. It only took one throw to get the line up and the antenna in the air. As it rose, the signal strengths came up, and the morse code got louder. We took a tour of the band, and then I went to 14.330 where I had said I was going to be. I called "Is the frequency in use?" twice, and when I heard nothing, sent out a CQ. BOOM, David, KW1DX comes right back to us. Several jaws dropped, and we started a pleasant QSO. The bands were a little funny, and we could never get over 55, but I did let several of the kids ask David questions. The neat thing was that David has a third grader in his family. The kids in the class made note of that.  We had a QSO on 20, and then we QSY'd to 15 with David, and signals on his end improved a little, but not a lot.

The kids had to go to lunch at 11, so we said our 73's and they went back to class. I got everything packed back up, and went home.

Portable radio is fun, and I'm glad I've had several opprotunities to work stations from the work parking lot. That prepared me to quickly and efficiently get the antennas in the air. For next time, I think I will focus on promoting the event, and try to have multiple ways of getting the word out, perhaps via the local repeater, and maybe even getting a couple of stations on frequency before hand.
I could also stand to lose some weight, trying to carry a box full of radios is hard work.

73,
GB Hoyt
KG4GVL


Tuesday, October 15, 2013

Sometimes it Pays to Check the Power Output!

The QRPARCI Fall QSO Party took place second weekend in October. I took an oppurtunity to participate in it albeit in a limited fashion. Mainly I wanted to test deploy my End Fed Half Wave antenna, and have some fun slingin' some dits and dahs.
20m Portable Operation, QRPARCI Fall QSO Party
 
Saturdays I work a monster 12 hour shift beginning at noon. After I got done doing some UI testing, and before the next batch of jobs I have to monitor began, I decided to take a half hour lunch break to feed my brain using ham radio, specifically the QSO Party. I sprinted out to "El Toro" (our red Mazda Tribute) after clocking out for lunch, and got to my station. This is the third time I've deployed in the parking lot using a wire antenna like this, and it was the first time I've used the EFHW to make a QSO from the parking lot. I made exactly one QSO, with NM4T on 20m. The EFHW did well over all, lots of signals, some were VERY loud, especially the SKCC WES stations near the QRP watering hole. I did make a couple of mistakes though.
 
1. I assumed I had everything I needed in my box. when I got out there, I realized I didn't have the connector for my 7AH gel cell battery. I did have the end that plugged into the radio, but not the end that plugged into the battery.
 
2. I could have used a second roll of fishing line. The EFHW works well on 20m with 33' or 66' of line deployed. I used 33' because I didn't have a way of stretching the second 33' section out, and time was too short to attempt a redeploy of the antenna. I didn't want to cut the line because I felt that would have been a waste of string.
 
3. I intentionally left my NoGAwatt at home, and I missed it. I like having the reassurance that my forward power is good to go. I would have checked, and then removed it from the line. I've discovered that it does add some non-trivial at QRP levels loss in the line, so I left it home.
 
Sunday I try to limit my "on the air" time in favor for some "play with the kids time" but I did take a little time to play radio at my in-laws from their driveway. We went over there to eat hamburgers, and the kids were playing as the sun was setting. This time I deployed on 40m, and confirmed my issue number 2: when setting up an EFHW on 40m as an inverted vee (It kinda looks more like a caret (^)to me) It helps to have two separate lines, one to support the middle, and one to support the far end. I keep a piece of paracord handy in the box to tie down the end where the RF goes.
 
Best Pic I have of my Sunday Night Setup
This time instead of using 20m I decided to go with 40, using "The Killer Watt Radio." It's supposed to be calibrated to transmit at one watt with the little 8 cell AA battery pack I use. That's with a fresh battery pack. I did take a better picture of my setup, but right when I snapped the pictured, my phone's battery died and it was lost :(. I did managed to get two QSO's on 40 before the skeeters got bad, and about carried me off. The first QSO was with WB4MNK, he was so loud, I had to turn the gain down to be able to hear anyone but him when tuning to people calling on nearby frequencies.
The second QSO was with N0WL. I had hoped that I could stay around and work him during the 4SQRP SS after the ARCI Party, but I could not stand the skeeters.

Monday morning I decided to check out my power levels and I discovered something interesting. The open circuit voltage on the battery pack was down to about 11.7 volts, and I was transmitting about .689 watts on both radios! This makes my Fall QSO party power multiplier a 10. Heh! that's one way to boost your score.


Here's what I learned:
66' of wire can be tough to quickly deploy without two support lines. I could have gone for a single support on the far end as High as I can get it, but I think I get some benefit from having the high current portion of the antenna (on 40m at least) at the apex. Might be worth modeling, if I can ever get a computer that will successfully run software.
  • Check and double check your kit, and make sure you have power redundancy. That saved my bacon both days, because I forgot the part that hooks up to my battery the first night, and then I forgot the part that hooks up to the radio the second night!
  • If you think you'll use it, bring it. I didn't technically "Need" my NoGAWatt, but I missed having it.
  • Bugspray is your friend, but having a layered strategy is better. Wish I had long sleeves, bugspray, and some sort of "area skeeter control" gadget with me instead of just bugspray. Them things are meaner now than when I was a kid!

73,
GB Hoyt
KG4GVL

Tuesday, April 30, 2013

Enough Time to Plan

W2LJ has announced that the NJQRP Club will sponsor the 2nd Annual Skeeter Hunt in August.

Could be a good chance to test some portable setup stuff I've been wanting to test out...
to be continued...

Tuesday, October 9, 2012

The First Annual 4SQRP 4X4 QRP Sprint

So,
I sprinted out my cube, into the parking lot, and partook in the 4SQRP club 4X4 Sprint.
:)
Here's what that means:
20m Vertical
My job is to monitor jobs using something called CA-7. (as a comedic aside, when people ask me what I do, I tell them "I push the L button... a lot", I know, it's not funny, but this is humor in my head) Each day, the jobs start at 6pm. On Saturdays I work a 12 hour shift. When I get in, yesterday's jobs are still running. I take a half hour break sometime after they finish, and before the next set of jobs begins at 6pm. I also take a couple of 15 minute on the clock breaks. I decided that I needed to use my 2 fifteen minute breaks for set up and take down, so that's what I did. I've tried operating from the work parking lot before. Haven't exactly been successful either. Mostly there's a time problem. Half an hour isn't a lot of time to set up, operate, and tear down. I've had to adjust my scheduling so that I get outside during a break, set up the antenna, and then come outside. Fifteen minutes isn't a long time to set up. I decided that since I was without multiband blackbox radio, or multiband kit radio, I would go monoband radio, monoband antenna.  The only setup I for that right now is 20m.

I get QRV^ on twenty because some time ago, I acquired an SW-20+ from AL7FS. He had an unbuilt kit, and was offering it at a fair price on QRP-L. I decided to buy it. I swapped the Killer Watt Radio* out for this, and have been using it for a while now. Turns out, I'd been a real QRP operator with that radio, because I thought I was putting out a buck and a quarter (1.25 watts) with it, but in reality, I was putting out 250 milliwatts! I had about 5 QSOs in the log with it before the 4x4 contest. After retweaking it to put out 1 watt with 8AA batteries for a power supply, I hit the field, hoping for a QSO. When I use the bench power supply, it's about 1.8 watts. The SW+ line is most efficient at 1.25, but can usually be tweaked out to about 2.2 watts without stability issues, if you heat sink the final transistor. I may decide at some point in time to put a diode in line with the bench PS, just for the drop in supply voltage, but not just yet. The Killer Watt Radio is in the wings though, it abides, waiting for the day I aquire Molex KK crimp terminals, but when they get here, and they are installed on the ends of my connectors... it will be awesome.

I needed an antenna that required minimal fuss to get put up. I tried the St Louis Vertical before, and while it's a great antenna for field ops, it requires some fussing with to get up up correctly. I've got some ideas for fixing it up right, but it's going to be a while before I get ready to work those issues out. When I get the Killer Watt Radio back in action, I'll go back to the SLV, until then, I use a 20m vertical. I choose to use the vertical design because they 'radiate equally poorly in all directions' or something like that :) I took a collapsible fishing pole I'd been using as a field antenna for 6m when I had an FT-817, and adapted it for 20 after building the radio months ago. I quickly discovered that I had been using poor math when planning the antenna. I knew I would be using just over 16.5 feet of speaker wire when setting the antenna up. I also knew that my fishing pole was 16 foot long, and that was close enough for me. Yippee, no worries! right? Wrong! When I initially created this antenna, I created it with with an elevated feedpoint. I did this on purpose. Why, I don't remember, but I know I had a reason! That shortened the usable amount of antenna length by about two and a half feet. I decided to ditch the top part of the antenna. It's Florida, and if I'm not at the beach, chances are, there's a tree near by, so I just stretch the radiator part up, and use the tree to keep it high. At home, I was able to get the SWR down to near perfect. In the field, I find that getting the radials deployed right is a little tougher, so I use an Emtech ZM-2 antenna tuner.
Battle Station!
 I tuned up my antenna on break, and went back inside to wait for my jobs to finish running. After it finished, and after I'd done some database wranglin' in preparation for the next run of jobs, it was time to QRV. This is where I literally sprinted to the sprint. Radio operators occasionally enjoy operating in radio contests. That's when they pit their skill against radio wave propagation and try to make as many radio contacts (QSOs) as possible while following a certain set of rules. One of those rules is usually some sort of time limit. A sprint is usually 4 or fewer hours. I've even heard of a "Russian Sprint" where you Work a station, then that station takes over the frequency and you QSY, thus keeping the frequency active with new callsign. I've tried contests before from the parking lot. Mainly, they turned into learning how not to quickly deploy an antenna in the parking lot lessons. I think I'm going to try to make it a regular habit to QRV during the Spartan Sprint (SP). Back in the day, when I had the Might FT-817, I would often get QRV during 'SP', using the full QRP gallon of 5 watts. I had a lot of fun. Now that I know what I'm doing at my job, and I know that I should be able to have some time to take a lunch break in the middle of the contest, I might try to get PLP (Parking Lot Portable) some more during the SP. I tried in October, but there was no signals audible on 20m. I did call CQ though, and I did get picked up on the Reverse Beacon Net (RBN), so it was good to halfway confirm that my signal was radiating. Last week, I heard about the 4SQRP Club 4x4 Sprint, and decided I was going to give it my best effort.

20m is a Daytime band, it needs some sunshine to really be effective, and I got outside at 19:30 UTC, 3:30 pm local. Tuning around I could hear several stations calling CQ 4S, and threw my call out there to answer them. Three of them actually heard me well enough to call me back!
I worked KB4QQJ who was the loudest signal I heard, a genuine S-9 Plus, and there must have been a pipeline to his QTH in North Carolina because he gave me a 599 too. I tried really hard for about 15 minutes to work WA5BDU but just couldn't do it. He was loud, about 579, but there was QSB, and I think that's what got him down. I did work WA0ITP. WA0ITP was the weakest station I could copy. He was usually about 229, occasionally he was 559. I gave him a 229, and he gave me a 559. Unfortunately, that was it for my operating time, so QRT for me, and I clocked back in. I went back out after checking to make sure nothing had exploded, and managed to work KG3W who was 559 to me during my second 15 minute break. I tore the antenna down, and was content with my three QSOs. After the sprint, my membership in the 4SQRP club was approved, so next year I will be worth more points!
:)



When I got back inside, this dude was sitting by the badge access reader:
You Can't See Me!
Purdy neet huh?
73


^ I make extensive use of Q-codes. Q-codes are a kind of short hand when using Morse code. A list of common Q codes is here.

* The Killer Watt Radio is an SW+ on 40m, originally given to me as a gift for my birthday the year we moved to the current QTH. It may only radiate 1 watt of RF, but that 1 watt is 1 killer watt! Once again, this is humor. Laughter is appropriate.

Monday, August 8, 2011

'Nother Awesome Portable Antenna Design - The St Louis Vertical




Whereas the W3EDP is my favorite antler, this one here is probably the one I use most often when I am in the field, mainly because it's so easy to deploy.
This is an antenna I first saw at a NoGA QRP meeting in Atlanta, when I first saw it, I thought to myself "Well ain't this the Bee's Knees."
The antenna is called a St Louis Vertical, named by the St Louis QRP Society, and enshrined at the American QRP Club.
This antenna is:
  • Portable
  • Easy to build
  • Easy to find the parts to build it!
  • Cheap (!kinda, not nearly as cheap as it was!)
  • Multi band
All of which are criteria I value in a homebrew antenna design.  It's best in the 40-10 meter band range, and I have used it on 40, 30, 20, 17, 15, and 10 with good results.  There are however, some caveats, and I would like to relate to you my experiences with it.

Take a good long look at the antenna, and you will understand that it is meant to be a bottom loaded 'short' vertical.  Here's the math though:

1. Do the Math, 1/4 wave vertical on:
40m: 33.29' (7.030 MHz)
30m: 23.15' (10.106 MHz
20m: 16.64' (14.060 MHz)
17m: 12.93' (18.096 MHz)
15m: 11.11' (21.060 MHz)
12m: 9.40' (24.906 MHz)
10m: 8.34' (28.060 MHz)

The only bands that this antenna is short on are 40, and 30M!
What this means is that the antenna will actually be LONG on 20M and up.

Long antennas get funny radiation patterns, especially as the frequencies approach multiples of wavelengths. Basically what happens is the signal stops shooting out (perpendicular to the orientation of the antenna), and starts shooting up. When the antenna is horizontal, that's not an issue, but when the antenna is vertical, it basically means the signal gets shot straight up into the air. Not desirable!
One simple solution to this problem is to use a shorter wire, or leave out the bottom loading coil. It's pretty easy to take a 20' fishing pole and make a quarter-wavelength long vertical out of it for frequencies greater than 14 MHz.

What I need to do to make it better on the higher bands, is find a way to measure the inductance of the coil, and working from there calculate a whip length, and adjust. Hmmm, the coil body is so long, that I have a feeling that trying to use the time honored method of measuring the resonant frequency when paralleled with a known capacitance value could lead to screwy values.  Maybe I need to measure series resonance instead...

I'll take anyone's help here.

Another thing that is slightly buggy sometimes, and can cause you no end of trouble if you aren't aware, is that best performance is obtained when you keep the feedline off the ground.  If the feedline can dance around, then you will notice strange SWR behavior.  I suspect that there is a large amount of signal loss to the ground if the line is allowed to rest on it.  I know signals sound louder when the line is elevated in some fashion.
The St Louis Vertical, took apart, and ready for transport:


Let me explain the parts:
You see in this picture, a "Sunny Day Fishing Pole" that's the brand name I believe. It extends to twenty feet.  Wrapped around the fishing line holder on this pole is enough stranded hookup wire to go from the top end of the coil to the top end of the fishing pole, around 16 feet.  It connects via an alligator clip. The four bundles of wire are the radials for the antenna.  They are made of 3 conductor antenna rotator wire, such as you find at Radio Shack.  The radials are made by attaching all three wires to a ring terminal connector and then nipping out an inch of the individual wires at various lengths along the way, making the longest 1/4 wavelength on the lowest frequency. You should apply electrical tape where you nip the wires to keep water out of the wire, and to keep the wires from pulling apart on a snag.  These wires are cut for 40, 20, and 15 meters, but they'll work 40-10 no problem.  You're using a tuner anyway!  The long spike is used to hold the pole up.  I use a hanger on the spike to keep the pole off the ground, and to also serve as a common lug for the radials.  The feedline is 300ohm twinlead.  The black alligator clip goes to the ground side, the red alligator clip goes to the radiator side.  The banana plugs go to my antenna tuner, usually an Emtech ZM-2.  I love that little thing!

I'm going to try something different with this antenna, namely, I'm contemplating elevating the antenna in some shape or form and making a permanent  antenna out of it.  This version of the SLV is traditionally fed with twin lead so that you can use a tuner to make the antenna work.  I might just keep that feature, maybe use the more robust wireman feedline, or something.

There is another version of the SLV out there, Here's a link to a "For Sale" article http://www.eham.net/classifieds/detail/341186 about it.  It's a pretty good little antenna too, a lot of hams on the old QRP-L reflector had one back around 200-2001.  I actually bought one from a guy on QRP-L in late 2000, but had the loading coil stolen from me before I had a chance to use it.  It was right after I got my general ticket too.  I had all sorts of plans in my head about going camping with it.  I bought some aluminum ground wire to make a new coil, but haven't made the time to do that yet.  There's always a project going on at my shack!

*******EDIT*********
I received this email from Dave, NF0R, the designer of the SLV.  He posted it to the QRP-L newsgroup, and I have reproduced it here with his permission:

Hello GB,


It appears you are having fun with the SLV. I enjoyed reading your comments and observations on the Blogspot over coffee. I'm retired now and have time have time to put a reply and update together this morning
I designed the SLV (1996?) to be a quick, lightweight and inexpensive vertical. It was for folks wanting to work a little portable QRP, make a few contacts and go back home. No heroics! Just enjoy radio in a portable setting without spending time finding a suitable spot for a wire antenna and still more time installing it. To that end I made it multiband with the continuous coil and a tuner to take advantage of propagation. It's no fun going out with a monoband homebrew rig and finding no signals on your band of choice. I got the idea for using the collapsible fiberglass pole from W7ZOI in Solid State Design.
Referring to your Blogspot you can use coax if you wish to avoid SWR issues associated with wet twinlead. Ditto for stiff line that tends to move around. But It's not a big deal - just tweak the tuner and gone. You can use twinax or parallel runs of RG-58 or even RG-174 if you wish. High-performance with a compromise antenna is always a bit of a battle. That said I tend to favor convenience for portable and working someone (anyone?) instead chasing
the coasts or DX.

I'm not much on elevating the twinlead feedline. As a matter if fact I may have not even tried that experiment. An elevated balanced feedline could add horizontal polarization sort of like an up & outer. But being so close to the ground I doubt it's practicality except for NVIS and prefer to rely on vertical polarization.

I have no idea what inductance the coil measures. It's really a moot point when feedling with balanced line. I filled the base of the SD-20 pole with twinlead because I had enough line in the Radio Shack package to do that. The wet thumb and/or more-is-better school of engineering if you will. It also allowed me to work 80M with the SLV a few times though I can't recommend
that.
The W6MMA wire coil is certainly more efficient due to it's elevated location. However, that particular product is not something you can duplicate without equipment and expertise. You can duplicate it's efficiency by winding a bare wire coil on a section of a child's round float tube and slipping that on thepole. That excellent and elegantly simple design was created by N0TFI (now AE0CW). His coil is a personal favorite of mine. It's real ham radio!
Note that with any tapped multiband coil you may have to swap out upper radiators when some bands change. This is not an issue with the twinlead coil. I prefer to operate when running portable and spend as little time as possible installing and/or adjusting the antenna. My design limit for installs is five minutes tops! Lately I have been running portable with a St. Louis Micro Loop where the set-up time is thirty seconds tops or about the time it takes to walk from the car trunk to a picnic table. For that and other reasons I really enjoy fooling around with that antenna. 
If I decided to re-do the SLV today I would use N0TFI's excellent homebrew coil mounted head-high for convenience. Setting aside most mono and dual-banders today's QRP xcvrs by and large feature on-board tuners. You can get a fairly close match with taps on the coil and touch up the match with the automatic tuner so the rig sees 50 ohms.
My other option would be to homebrew a tapped air-core St. Louis Coil for the SLV which I have already done in multi-band and mono-band versions. These elevated configurations produce very efficient antennas. I also use my version of W6MMA's built-up SLV mount. It employs a pcb feedpoint disk for attaching St. Louis Radials and protects feedline
connections in wet weather.

There were no integrated tuners in commercial QRP xcvrs when the SLV was designed. Hitting tap points on a coil when portable is inconsistent The antenna was intended to be erected in any number of locations and each site is a different RF environment. Having said that there may be
some who still enjoy running back and forth between the antenna and the rig to get a low reading on the SWR bridge. For that and practical reasons I like to keep my portable vertical feedlines short - typically 12-18 feet depending on the lowest design band.

I increased the original SLV's folded radials from three to eight for better efficiency on 30M and 40M. I dropped the notching after several EE's kindly took time to explain how ground proximity affected the resonance of radials laying on the ground. Those folded radials evolved into St. Louis Radials which use ribbon cable. They put a lot of wire (metal) under the antenna which seems to be helpful judging from several field strength experiments. However,
the main reason for their existence is to minimize the hassle with single wire radials and those annoying tangling problems out in the field. Grrrr!
Being fairly supple the stranded-wire ribbon radials are much easier to store, carry and deploy than twinlead. On the trail I coil in groups of three and carry in a round rubber container in the backpack. Otherwise I gather them right below the alligator clips, lower into a cloth bag and
store in the car trunk.
I actually use 1/8th wave radials these days for my portable antennas including the St. Louis Vertical, St. Louis Vest Pocket Vertical, St. Louis Express and several more unpublished designs. These short radials work remarkably and were suggested to me by KK6MC, Jim Duffy, a.k.a. Dr. Megacycle'

I have no qualms running a 10' tall SLVPV on 30M and 40M for chasing DX or milliwatting with eight to a dozen abbreviated ribbon radials under it. For all of these portable verticals the footprint ends up being very small.
Thanks very much for your post about my old SLV. I certainly enjoyed reading it and appreciate your time and effort. I hope you find my comments helpful.
Best regards,

Dave Gauding, NF0R

Ain't this a fun hobby?