Sunday I got the itch to get online. That means backyard portable when you live in an antenna restricted condo. So I put a card table up in the back porch and my 20 ft Jackite and 20m End Fed Half Wave in between the buildings.

Doggone noise and weak band conditions ruined the day so I decided to experiment with the new C Pole antenna that  Neil W0VLZ had suggested. To get rid of a hunk of fiberglass gel inside the barrel of one of the Black Widow Crappie poles I used my cheapo Harbor Freight rotary tool which is a lame imitation of a Dremel tool but gets the job done. A few minutes of fitting and I was good to go.

I’m pretty impressed with it though conditions did not allow for any QSO’s yet. I cut the wire a bit longer than Niel’s directions but it tuned up 1:1 at 13.889 on my MFJ 207 Analyzer. At 14.060 it was a bit over 1.4:1 which is plenty usable. Next time out I’ll do a bit of trimming and be right on the money! Compared to the EFHW in a 20 ft L configuration, it did seem a bit noisier but with condx so difficult it would be hard to tell without some instrumentation.

LESSON: The C Pole is a pretty fine design. I need to work on the physical setup to improve the way the antenna hangs. The crappie poles I used were a bit too flimsy on the top section and leaned inward from the weight of the wire. A better tippy top support system is needed.

LESSON: Niel’s C Pole base design and specs worked very well.  Lacking an empty plastic coffee can, I used a quart diet soda bottle of the same dimension and it worked very well for the balun section. With winds of approximately 15 mph and gusts to 20+ the antenna was stable and I did not use the spikes for the outriggers that I had prepared. Great work Niel. The weight of the base makes it a good choice for backyard or campground use.

LESSON: The C Pole would be a fantastic portable antenna sans the earth side supports. Chuck Carpenter W5USJ has posted a picture of this configuration. Take a look. One point hanger  and spreaders at the top and bottom and simple stake to the ground for anchoring it and you are good to go. I will be testing this next time out by the lake. Winner!

LESSON: The off center fed dipole folded like this and deployed vertically is a good compact option for antenna restricted hams. I bit more work on the frame and support system may pay good dividends in stability and efficiency.

Hope to fly this new antenna in its tree configuration this weekend. I’ll update my results then.

72,

Kelly K4UPG PB #173

Back in 1964 as a novice, it seemed like the strongest signals I heard in Central Indiana were the Florida stations. Man, seemed like they were always there, louder than anything else. As a new ham and teenager, I always thought how cool it would be to live in Florida, the land of fantastic propagation.

Memory Lane...The First Rig

Sure been disappointing lately… the bands are noisy, the thunderstorms consistent and sometimes it seems like no one else is on the air. What happened to my Florida ham radio paradise dream?

Are the bands working elsewhere? Boy, we have had some poor conditions lately. How about you?

On  a high note (pun intended) it was pretty cool to watch QRPSPOTS.COM yesterday as lots of hams helped give signal reports to the Iowa High Altitude Balloon launched by W0OTM team! Congrats on creating some excitement and interesting reports. Now, if I can just get my antenna up to 30,000 feet or more, maybe my FL QTH will be ham radio paradise after all.

72,

Kelly K4UPG PB #173

This is the first of a weekly (Lord willin’) post of some of the lessons learned in the last week of playing radio in the field and on the workbench. I will be sharing my good and some of the not so good lessons with ya so ya don’t fall into the same holes that I have.

Our monthly Polar Bear QRP Club outing was last weekend, and I hustled to put together a new C Pole antenna using Niel W0VLZ’s description. After gathering all the parts I set about preparing them. With the 100F temperatures and high humidity, that was a chore since I don’t have a garage with my condo and use my back porch as the workshop. I also have a less than full set of tools and to trim the 3/4 inch PVC pipe to fit the bases of the 16.5 ft Black Widow Crappie poles I had to resort to my Buck knife.

LESSON: Plan ahead and borrow the tools I need!!! YIKES.

I was a bit surprised how heavy the treated 1×4 lumber was. It certainly is not an antenna that is well suited to portable ops where it has to be carried very far.

LESSON: Think about how something is to be used BEFORE using it!

Got the C pole components loaded into the car and transported to the nearby lakeside park in our development. It is a nice quiet spot with towering pine trees and without too many curious visitors, so its a nice QRP portable site. Got my new Coleman shelter set up and went to work on the C Pole. Oops… another lesson. In preparing the PVC to fit into the crappie poles, I only tested the two pvc poles fit into ONE of the two crappie poles. After lugging the framework, antenna wire, coax, balun,  and poles about 100 yds to my site, I discovered crappie pole #2 had a big drop of fiberglass inside the open end of the pole and the PVC would not fit at all.

K4UPG Polar Bear Site Aug 2010

C Pole Aborted Setup by Ninja wannabe K4UPG

LESSON: Check ALL the parts and do a trial setup BEFORE lugging the stuff across the wet grass and wasting time attempting to set it up.

LESSON: Don’t use a new antenna for the first time when the goal is get on the air and have fun!

For the Polar Bears, it was a frustrating weekend for most of us. Propagation was spotty and noise level was as high as the heat. At least I did reconnect with my antenna lovin’ PB friend Aaron, N9SKN/2 working from his hotel parking lot in NJ and had a couple nice ragchews including Julio NP3CW who was 599 and despite two guys calling CQ on top of us was able to be copied well. Great QRP signal Julio.

As you can see, I went ninja and tied a piece of old tee shirt around my head as a sweatband. Actually I was emulating our Alpha Bear, Ron WB3AAL after I read of his early Appalachian Trail exploits and saw a photo of him in his youth and ninja radio mode. Well I tied it TOO TIGHT and left it on TOO LONG and came home with a painful big red stripe on my forehead that lasted for several hours and hurt like all git out.

Ouch Head for the Web... Don't try this at home! Grrrrrrr!

LESSON: Baby Polar Bears should not try to be like the Alpha Bear and wear an unapproved homebrew sweatband. These can be hazardous to one’s health and well being. Don’t try this at home kids!

Beef n Pepper Jack Cheese Wrap K4UPG style

p. s. For our Summer Picnic Events, we are supposed to send a picture of our sammich that we have for lunch. So here is mine!

Until next time…

72,

Kelly K4UPG Polar Bear #173

Here’s an email from my good friend and cohort in the Central Florida QRP Group. Jim wanted to share his latest mods for the Rockmites and some thoughts on the NEScaf filter. I think you will enjoy his notes too …

Kelly,

I thought I would bring you up to date on my latest project. I just finished a Small Wonder 20+ and used it on the Flight of the Bumblebees. I found my earbuds a little weak on audio output and the IF bandwidth of the SW20+ a bit wide for my liking. I read the specifications on the NEScaf filter offered by the New England QRP group and decided that that would be the best solution to my problem and be usable on other radios as well. I ordered, built and installed the NEScaf board in a TenTec TG-24 enclosure. I tried it on the SW20 and it sounded like a viable solution.

The Rockmite and NEScaf filter in Ten Tec Enclosures

I also have a 40 Meter Rockmite in a TG-24 enclosure and decided I would see how well the RM/NEScaf combination sounded. The Rockmite, of course, uses a DC receiver and the bandwidth is determined by the upper response of your ears… My RM sounds like about 40 khz wide, hears the whole band for me as my response is in the upper tens of kHz. Yes, I know, at my age 69 it shouldn’t be but is. Been tested. At any rate suddenly the Rockmite bandwidth is manageable. I had some audio artifacts, whistles and the RM sidetone would drive the NEScaf into cutoff which only a power cycle would clear. I googled the problem and Charlie KE2SP advised lowering the NEScaf input Z with a 10 to 47 ohm input load. I installed a 27 ohm resistor on the input connector and suddenly all artifacts, whistles and sidetone problems disappeared. WOW, the RM is really sounding great! Except the RX/TX was very low. I measured it at 500 cycles and the NEScaf would not tune down that low…

Closer Look at the Finished Rockmite and NEScaf

After considering several approaches to the problem and considering that the RM crystals don’t oscillate on exactly the QRP frequencies, I settled on completely revamping the RX/TX method used in the RM. Using the RM40 as a test bed, I removed D5, D6, R9 and R10. I purchased 2 Murata trimmers( TZ03 Series) from Skycraft, our local Surplus emporium, and installed them in the holes for D6 and D5, R9 combination of holes. I had to cut a small run on the right side (antenna connector side) to isolate that pad from Vcc and jumper to two trimmers together… I also had to drill out the pads to accept the trimmer leads. The Fet Q2 does a great job in switching to second trimmer in and out for the offset. The alignment was not difficult but I recommend using a freq counter connected thru a times 10 scope probe to the physical top of R5 (base of Q5). Don’t have to key the Tx to see the freq… I set the trimmer in the D6 position for the higher freq (7.030750 Mhz) and the other trimmer for the lower frequency (7.030000 Mhz. The trimmers I use are available at Digikey. I used the Red colored model (4.2 to 20pf, N750) but the Blue colored (2.7 to 10pf, NPO) might have been a better choice. These guys are Digikey p/n 490-1971-ND and are $0.43 each… I also changed the RM40 volume control from an audio control (1 Megohm) to a RF front end attenuator control (1.5 kohm) and there is a noticeable improvement in the overload and broadcaster breakthru problem. I strongly recommend these changes. If you can build the RM you can certainly modify it… If you break it, build another… I plan to make the same modification to my RM80. (CLICK THE THUMBNAILS for larger view)

Rockmite Mode Closeup 1

Rockmite another closeup

The Inner Workings of the NEScaf and Rockmite

How did it work? Well, the RM/Nescaf stack is now a real radio not just a toy. I worked WD8MHT Raul in Waynesville, NC one morning this week and we had a great conversation. He was 569 to me and I was 439 to him. His TS570 was working hard but copied me no problem. The amazing thing for me was that there was a really strong signal at 700 cycles and Raul was about 200 cycles higher. I tuned the Nescaf center freq on Raul and sharpened the bandpass and turned up the volume and he was armchair copy the entire QSO… WOW, not a struggle… I have since used the NEScaf on my SW20+ and yes, it works great…

I have attached a couple of pictures of the stack and the innards of the RM for reference. The switch on the front is for a future expansion.

72

Jim

K4AHO

Now into the third week of my sabbatical, I am surprised how much I want to get out and operate my QRP portable gear. Guess I have deprived myself over the years of being a confirmed workaholic and avoiding time off, vacations, and time for my favorite hobby.

Grrrrr! The Polar Bears Are On The Loose!

This should be a good weekend for QRP portable. The Polar Bear QRP Group will be out for another Polar Bear Summer Picnic Event and Polar Bears from Spain to the West Coast of the US will be out looking for BSO’s. Grrrrr! I am PB #173 and we’re over 200 members now. With the new Twitter and APRS connections to QRPSPOTS.COM which also point to the excellent spotting site of K3UK with a section for FISTS/QRP Ops to spot and sked one another, there are plenty of ways to use technology to help find each other. Add in a few other contests and state QSO parties, and there should be some buzzing going on this weekend. Makes me wonder when the FOBB results will be announced! Buzzzz Buzzzzz

I’ll be out and if all goes well I will be field testing a new C Pole antenna based on the suggestion I received from Neil W0LVZ. I added some switchable capacitance to my BLT+ and have rewound the main toroid to see if I can push the range a bit more with it so will have a delta loop and probably my W3EDP in the air too. I love playing with antennas and am still amazed when the ones I build actually make contacts!

Give a listen for me on the QRP watering holes on 40m, 30m and 20m Saturday morning. I’ll be self spotting on QRPSPOTS and the K3UK sites to make it easier for you to find me. Let me know how my newest antenna is workin’.

72,

Kelly K4UPG

PB #173

After last week’s plea for antenna ideas for my antenna restricted condo, I received a good number of comments both on and off blog. Thanks for those… great food for thought. That is why I enjoy our QRP community. We don’t hesitate to share ideas with one another.

This morning as I took my daily walk around the lake, I met our condo association president. He graciously is allowing me to sink a pipe that will serve as a base to set up my Jackite poles in the backyard. I will be able to pop a cap on the top and keep the dirt and water out and just slide my fiberglass poles into the mount and be on the air in no time. YAHOO… that is a pretty good solution for now.

C Pole Antenna by W0VLZ

But being the antenna tweak that I am, I continue to look for the best alternatives I can find. I’ve started to put together the parts for the C Pole antenna that Niel W0VLZ pointed out to me. He has a fine site with lots of good QRP info too.

So, do you have another idea that can top that one? Or maybe you have a thought for what kind of vertical setup I might use with the new mount?

I’m standing by for my next project assignment.

72,

Kelly K4UPG

One of my favorite QRP groups is the 4 States QRP Group that sponsors Ozarkcon. Today we had an interesting thread going on their email list concerning slingshot antenna launcher and visibility of the line and sinker.

I’ve been working on that issue for a bit and offered my current solution. Still not 100% perfected, but it is working well now. Here in Florida, the tallest trees are mostly pines and the bark is pretty sticky with sap and lots of crooks and crannies that don’t allow monofilament fishing line to slide as freely as I’d like. I’ve tried the archery reel and slick braided line and although it does slide nicely through the trees, it is much slower and challenging to reel in and also is very prone to tangles and wind knotting which wastes time to untangle. In low wind or super sticky pine trees it is still the best solution.

Below are some photos of my cheapo solution to the slingshot line launcher. A $4 slingshot from Harbor Freight and a 99 cent shelf bracket from Lowe’s are the basic components. One challenge is being able to see where the sinker and line end up after the shot. I tried painting the sinkers, but in tall grass or lots of leafy trees, it did not show up as easily as I would like. The simple solution I found was to use fluorescent plastic surveyor’s tape (also from Lowe’s) to add both vivid color and some motion to help me locate the sinker whether in the trees, air or ground. I’ve also recently switched to red colored monofilament line called Cajun Red Lightning that offers a bit more visibility than clear monofilament.

Here are the basic elements... slingshot, Shelf bracket, spincast reel

If you are looking for an inexpensive simple solution, this might be the answer! Give it a try and let us know how it works for you. Leave a comment or better yet, join the 4 States QRP Group and join the conversation.

Closeup of the mounting of the reel

The assembled launcher -- slingshot taped to bracket

Had a good day in the park with Jim K4AHO and Wally KG4LAL. Spent a good bit of time testing a couple tuners for End Fed Half Wave antennas using Jim’s AIM 4170. Wow is that thing a great tool for tweaking antennas! Info overload!

I built an antenna tuner based on AA5TB’s design for an end fed half wave antenna. I am using a 3 ft or so counterpoise on the ground as Steve suggests. On the analyzer in a test lashup it was a bit touchy to hand capacitance but tuned well even up to 21Mhz. Since I am not thinking of backpack size I used a pretty good sized enclosure for it. I am using an air variable 6-160pf cap instead of a polyvaricon like Steve used since space is not a big issue. I also used a T68-6 toroid instead of the T50-2 Steve used.

When I mounted it in a plastic box the sensitivity seemed to increase. I have not put a LED SWR bridge in the box yet, as I was waiting to see how it worked before adding more variables. Today I was able to put an AIM 4170 analyzer on it and it did tune the antenna… seems that the air variable I used is perhaps a tad small. It is almost fully meshed on 40m cw and on 20m it acts like even at minimum capacitance the sweet spot is very narrow and hard to tune.

Here's the innards

My question(s) are:
1) Is the hand/body capacitance normal? If not, what might cause it to
be so touchy?
2) Would my parts layout be part of the issue?
3) Does the DPDT switch (mini toggle) I added for later use with the SWR
bridge add significant capacitance to the circuit? I was able to match a
21Mhz load on the raw test setup, but not once it is in the box.
4) I have a small bus wire for a ground, do I need to increase that?
5) Is the plastic box the problem? Would it be better in a metal enclosure?
6) Am I asking too many questions? Sorry, this is how I learn. Build,
test, ask…

SWR bridge I want to use

Thanks for your wisdom and experience on this one.

72,
Kelly K4UPG

My favorite QRP group is the Polar Bear QRP gang! We have a good time and enjoy outdoors activities and trying to connect with one another at least once a month with some kind of activity. To escape some of the heat, I got an early start on the day. I wanted to try out a new mini-bac antenna configuration and knew it would take some time to get it up into the trees. BOY WAS THAT AN UNDERSTATEMENT! It was 110 ft doublet with a 40 ft feedline that was setup as a ladder line. Not an easy one to get up single-handed. Thanks to some tall trees, was able to get it up about 40-45 feet in the pine trees. It loaded great on 40m, but was disappointing on 20m so I ended up setting up my W3EDP in an L from my 20 ft Jackite pole to a nearby cedar tree at about 35 feet.  The sun chased me into the treeline where I settled in to chase bears.

Abandoned mini-back doublet feedline hangs in foreground

My xyl Connie took a picture that shows the mini-back feedline hanging in the breeze after I shifted positions and setup the W3EDP in the shade. Grrrrr!

Osprey perched right above my head...cell phone picture

Was able to work a couple of the Polar Bears, Mike W3MC in MD and Guy N7UN up in the mountains on a trail(?) in NJ. I heard VA2SG but he was at ESP level briefly then faded away. I did hear a few others working him though. WA8REI was working Guy but I could not hear him at all and ended up tail ending their QSO to connect with N7UN.

Got to work a few others through the QSB and poor signal strength on 20m including Pastor Les, K4NK in SC, KE5SBZ, Ed in TX, N1FJ in MA, and Phil W3HZZ in Atlanta so it was a nice way to spend a few hours outdoors in the heat.

Connie brought me a picnic lunch and we enjoyed the osprey and bald eagle show as they fished Lake Fredrica.

Had to drink extra coffee to copy speedy W3MC's signal

This is the life... outdoors and ham radio...making QSO's...PTL!

Look out Hontoon Island the Polar Bear of Florida is coming your way! Good Friday, 2 April 2010 Polar Bear QRP member #173 (aka K4UPG) will attempt to qualify Hontoon Island as a US Island on the Air by making 25 contacts including at least 2 DXCC entities.

Hontoon Island is a beautiful place for some QRP Portable Ops

Activity will start about 1400Z after the ferry ride over to the island. Plan is to use special callsign K4T for recognition.

Look for us on 30m cw (10.106-10.116 MHz) and 20m cw 14.050-14.070 MHz and on the hour we will check 15m 21.060-21.070. If anyone shows up to assist, will also attempt ssb on 14.250-14.260 MHz island corridor. All ops will be QRP so we’ll need your help to pull us out!

***************************************************************************************

Fishing is good!

If things go well, our Central Florida QRP group may consider this as a new operating site! If you are in the area, come on and check it out with us.

Hontoon Island closes when the sun goes down!

Thanks to Florida State Parks for the fine pictures!

P.S. We did it 4.2.2010!  Over 30 QSO’s update coming! I am TIRED!