Iowa High Altitude Balloon Project

One of the 4 States QRP bunch, Terry WA0ITP, provided the 20m beacon again and has some great info on his informative website.

But for me, the coolest thing was listening in on the streaming webcast of  VE3EN and his wonderful IC-7700. Sure wish I had thought of recording a bit or doing a screenshot to share here. But what a treat to listen in and hear the beacon’s signal right up until touchdown. Thanks Kevin for a fun way to eavesdrop on this event since the lawn mowing crew took over my condo’s yard and didn’t allow me to put an antenna out today. There is a ton of info and creative website construction on Kevin’s website and it is worth spending some time looking at the solar cycle data.

Congrats to the team for a successful event today and for bringing so many hams together for a good learning experience and something out of the ordinary. Well done W0OTM, well done indeed!

I am a rookie homebrewer. My kit experience is good, but I have struggled to build direct from schematics. Part of it is my lack of ability to conceptualize the physical layout and part of my challenge is lack of building experience and mentoring.

What should I use?

Several of my antenna tuner projects seem to have a TON of hand capacitance effect. They are built in plastic cases, some from the Shack and some from the local surplus shops and hamfests. Most commercial tuners are built in metal cases and I wonder if that would eliminate the sensitivity to the tuning hand?

I have a couple metal enclosures I can use and a great ham friend sent me some thin copper with adhesive tape on the back.  I am thinking of slapping some copper tape inside the plastic cases and see how it works.

So, I am putting it to the vote:

And for the record, the vote in the poll  for best ham radio QTH in the US was won by West Virgina. Here is the top 5:

• West Virginia (17%, 11 Votes)
• Kansas (14%, 9 Votes)
• Texas (8%, 5 Votes)
• Hawaii (6%, 4 Votes)
• New Hampshire (5%, 3 Votes)

Thanks and 72,

Kelly K4UPG

Bands were decent with 40m quiet and some DX coming through early from Eu stations. Nice to hear that again. 20m came alive and was pretty much the go to band for the majority of the day. I did check 15m a couple times but did not hear much and no one replied to my CQ’s.

In the middle of a QSO, my Jackite pole decided to collapse but I was able to finish the QSO with one end of the dipole about 4 feet above the ground. hi hi

The highlight of the day was my last QSO with EA3NO, Lluis in Spain. As the special station for the sprint there was a lot of competition but Lluis hung in there with my weak signal and pulled me out of the crowd after a couple attempts. THANK YOU FOR THE BIRTHDAY PRESENT Lluis!

Still wondering what a CPG is? Contest Point Giver! I am a really casual contester. Really the only reason I participate is that contests offer a fairly good opportunity to make some QSO’s. When you are QRP you have to do a lot of listening, plus pounce and search, but serious contesters will dig out weak signals to make the QSO’s so it is fun. I enjoy giving out points and reading the mail on ops that are faster than my cw comfort zone. Good practice, eh?

Here’s some photos from the day. Enjoy!

[Show as slideshow]

[View with PicLens]

72,

Kelly K4UPG PB #173 SKCC #5415

LESSON: A good analyzer makes tuning an antenna fast, simple  and accurate! The AIM 4170 gave us a TON of info (most of it going over my head) and let us see how the C Pole was doing in several areas.  Take a look at this output! (Click on the image for a larger version)

K4UPG C Pole Scan Results

LESSON: I followed Niel’s directions, but did not have a small plastic coffee container so used a Quart Coke bottle instead. So I call it a Coke Choke and it seems to work well. Here’s a photo to show it off!

Coke Choke Ready for Duty

I think this one is a keeper. Goes up easily, hears well and loads nicely too. I made a few brief contacts and called it a day, but look forward to more C Pole action in the days ahead.

72,

Kelly K4UPG PB #173

p.s. Don’t forget to vote in the Ideal Ham Radio QTH poll on the blog!

Some time ago I purchased a Deluxe Tuner kit from Dan’s Small Parts and Kits aka a QRP Mini Tuner by Mark L. Meyer as described in a 73 magazine article. It is a nice little set of parts and a schematic for the price.

QRP Mini Tuner Kit

So I’m thinking this holiday might be the time to build that little T tuner out and see if I can load up the downspout that runs down the side of my back porch. I’ll let you know how it works!

Hope the bands hold up. Tonight’s QRP-L has a message from N4QA about how nice 40m is sounding right now! Sure would be fun to have our bands back from the QRN and low sunspot streak of late!

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

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

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

Great that we have some holidays and time off as it allows a bit more opportunity to get on the air. The MI QRP group hosted a 4th of July Sprint and although the hour was late (7-11PM EDT) since I did not have to go to work Monday, I took advantage of the chance to work a few of my fellow QRP ops.

Rain and lightning welcomed my efforts to set up an antenna. So I forsook my normal setup and settled for a twinlead 44 foot doublet hung from my 20 foot Jackite pole which was bungee cord strapped to a ladder in the back yard of our condo. The antenna ran north south so much less than ideal, but at least I could get on the air.

Freshly Built NEScaf saved my bacon!

The day was saved by my freshly built NEScaf filter. As one of the lucky ones, I recently received the latest edition of this great kit provided by the NE QRP bunch. It enabled me to listen to cw despite the high QRN and background hash from neighbor’s TV’s, computers and air conditioners. What a joy it is to actually hear stations through the noise. This is a must have accessory for the condo based QRP op! I am still learning to use it well, but am mega-impressed with the capabilities it offers. With this audio filter, I could null out the QRN and peak the CW signals making for much more relaxed and enjoyable copy. The extra audio boost helps my little Sierra audio too. Keep watching for the next round of kits!

My Oil Change Parking Lot QTH for 30m

A quick tune found a couple week signals. I tuned the antenna a bit, called CQ with no luck, then heard a decent 579 signal calling CQ. Bill, NG3O in Columbia, MD replied and although I wasn’t strong (539) he thought he could copy me. He sure did a great job and we enjoyed a nice QSO for almost 30 minutes. Sure is pleasant to work a good fist without any QRM. He said I was his first Oil Change Parking Lot QSO.

A few minutes later, I connected with Rudy, W8RJW in Columbia, SC. He was a strong 589 and gave me a 559. We had a nice qso for several minutes too. It was a fun way to pass the time while I waited on my car maintenance to be done.

The band got pretty quiet afterwards and though I heard a few more stations, it was time to pull the plug, take down the wire and go home. I think I have figured out a new way to pass time when the opportunity is present. Hope you will give it a try too!

72,

Kelly K4UPG