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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

We purchased our condo before I got back into ham radio. Like most in Orlando, we have antenna restrictions. I can put up portable or temporary antennas but cannot mount anything to the building permanently. I’d love to be able to get on the air without all the hassles of dragging gear to the porch, setting up an antenna and then tearing it all down again. It takes so much time to setup and tear down that it turns a few minutes of operating into a long process.

Here’s the layout I have to work with at the QTH…

The front yard view… I am next door down from the blue car

Preferred antenna site is the backyard

The buildings run north and south and these photos are shot facing due north. My condo is ground floor, second from the south end of the building. Yes, that is a big electrical transformer box and a major underground feeder line runs to it from the north.

I’ve used my Buddistick with some success but it doesn’t like being so close to the buildings and the swr is higher than when it is out in the open. I also have run a doublet inverted vee fed with twinlead but the north south orientation is not very favorable from my Florida QTH and sends most of my rf into the two buildings. My W3EDP works fairly well as an inverted L with my 20′ Jackite pole and I’ve used end fed halfwaves as slopers and inverted vees but again the directivity is not favorably oriented. I have a 3 foot magnetic loop propped against the wall but it is not working as well as I’d like yet. (i.e. the outdoor antennas work LOTS better so far)

Thought I’d ask ya’ll for some input.

Any outrageous ideas or thoughts for  me? Send me a comment and let me know.

Thanks in advance for your thoughts.

I still think the tin foil does the magic!

After years of neglect, this analog era ham is willing to admit I only understand a bit about digital electronics. (Yep! Pun intended.) Well into the second week of my sabbatical leave, I have begun to plot out a course of study to get up to speed on the state of the art that I have so long neglected. Should be fun. There seems to be a good bit of open source help online these days and I have my trusty ARRL Handbook, Extra Class study guide, Antenna Handbook and assortment of other aids.

Any suggestions from the veteran techies out there will be greatly appreciated.

I am a learn by doing/hands-on sort of guy and find deep theory puts me into a semi-catatonic state after a few minutes.  For me, it’s a whole lot more fun to take a stab at things and find out if they smoke, and it also makes a lot more sense when I can dink and tweak and see what that actually does. But since that is a bit expensive, perhaps I should learn how to use software like spice to do simulations? Any recommendations for how to learn this software?

Another area of toe dipping will be learning to do antenna modeling. For years I’ve looked at those charts and made little sense out of them. HA… I like to throw wire out and see what happens, but in the summer heat, maybe it is wiser to do a bit of modeling from my air conditioned den?

Thanks WX7S– Your site looks AWESOME for learning this stuff!

I’ll try to share some of the learning curve, but would love to hear from some of you that have gone before. Shortcuts are nice. WX7S your site looks like a great place for me to start! Thanks for the effort it takes to do that.

This weekend (Sat 14 Aug 2010) the Central Florida QRP Group will gather for breakfast at 0730 (Denny’s in Sanford, FL) and off to Sylvan Lake Park in Sanford, FL at 0900 EDT to operate. If you like cw and qrp or are just plain curious… come join us!