AmateurRadio.com

Why do some people find it necessary to put some irrelevant quote after their signature in forum and mailing list postings? When you see posts from these people several times a day it becomes incredibly irritating.

One person whose posts I seem to encounter frequently has two quotes after his signature: “Whoever said nothing is impossible never tried slamming a revolving door!” and “A government big enough to give you everything you want, is strong enough to take everything you have.”

I can’t say I ever found the first one very funny but it has got very old after the 100th viewing. And I didn’t join a ham radio mailing list to learn about people’s political opinions, whether or not I agree with them. So please, just stop doing it.

Welcome to Handiham World!

Telling the story: Mike Runholt, KC0YFV, on ARRL website

Photo: Mike, KC0YFV, left, and Bill, N0CIC, take down one of the wire antennas following a memorable radio camp session at Courage North. This radio camp was the last of a long run of week-long camp sessions at the Courage North location. In 2010, the radio camp session moved to Camp Courage, about 40 miles west of Minneapolis, Minnesota. Courage Center owns both camps. The Handiham System headquarters is at Camp Courage.

Mike Runholt, KC0YFV, has written an excellent article about the Handiham System and Radio Camp. It appears this week on the ARRL website. You can reach Mike at his callsign at ARRL.net if you wish to comment on the story.

“The pontoon slowly motors around the lake. A group of hams gathers around the radio. “CQ, CQ 80 meters this is W0EQO, KC0YFV at the mike, maritime mobiling from Courage North in Lake George, Minnesota, over.” So begins a typical contact at the Handiham Radio Camp sponsored by the Courage Handiham System, a program of the Courage Center. You have probably seen our quarterly ad in QST and wondered what we do.”

Read the entire story on the improved and newly-redesigned ARRL website.

Our thanks to Mike for telling the Handiham story so well. Good work, Mike! And, hey, Bill, you look good in that photo, too. Are you the wire tangler or the wire untangler?

The National Museum of Computing at Bletchley Park has found a use for 30-year-old BBC Micros – teaching students how to write programs. One ICT teacher said: “The computing A-level is about how computers work, but if you ask anyone how it works they will not be able to tell you. Modern computers go too fast. You can see the instructions happening for real with these machines. They need to have that understanding for the A-level.”

I often think back wistfully to the days of programming early microcomputers where each instruction or subroutine you wrote had a direct effect on the hardware. Even the way things appeared on the screen were a direct result of my own coding. Today, Windows manages all input and output and actually prevents the programmer from directly accessing the hardware. In modern programming you never see a machine instruction. It’s all done using high-level language commands to set the properties of “objects” – software “black boxes” that simplify and speed up complex programming tasks but hide the mechanics of their operation. You couldn’t write modern software the old way, but I still miss the simplicity of early computing.

I have pretty similar reasons for being concerned at what developments like SDR and D-Star will do to the ham radio hobby. The technology is so complex that the average amateur will have no understanding of how they work, only how to use them. I miss the days when you could open a schematic and follow the path of a signal from one end to the other.

Of course, you can still buy kits to build simple radios. I hope that there will always be a place in our hobby for simple, analogue radios that the average amateur can understand, and I don’t mean just in a museum.

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

I think it is important when operating a ham radio station from home to ensure that none of your own domestic equipment suffers from interference. It’s a sign that everything is OK, and if a neighbour should complain then it helps to prove the point that it is not your fault if you can demonstrate that your own TV, phone, stereo etc. are not affected by your transmissions. I’ve been surprised at the amount of power I’ve been able to run using antennas in the attic without experiencing any problems.

Last night I decided to use the digital DAB band of my radio tuner to listen to the Promenade Concert on BBC Radio 3 because Olga complained of hearing some high pitched noise (inaudible to me) on the analogue FM band, when played through a stereo amplifier and a pair of large 40 year old IMF monitor speakers. For a few minutes it was fine, then there were a couple of interruptions to the broadcast which I guessed were caused by the transmission of my APRS beacons. I think that the DAB transmissions are quite close in frequency to 2m so I shut down the 2m APRS gateway and we enjoyed the rest of the concert without interruptions. I imagine that the neighbours, if they listen to radio at all, will use analogue FM just as we normally do, but it is a bit of a concern that just 10W of 2m FM can cause interference to anything.

The only other known problem caused by my radio transmissions is a neighbour’s security lights. I imagine this is a common problem. I installed an identical looking PIR controlled security light at the front of the house a few years ago after a couple of drunk youths wandered up our cul de sac one night and decided to uproot some of the plants in a neighbour’s garden. I found that I could turn the lights on with as little as 5W on 20m. The solution was to leave our lamp turned off and hope that the neighbour thought it was the wind blowing the bushes around that was triggering his ones. Fortunately it is often windy here and I didn’t used to go on the air in the evening all that often.

But my APRS gateway runs from morning to night and runs 50W output on 30m so the problem will become more evident as the nights draw in unless I adopt the simplest solution which is to shut it down (or switch to receive only) at nightfall. Breaking cover by admitting to a neighbour that I have been causing this to happen risks opening a can of worms that could put me off the air entirely, and remedying the problem would be expensive as his lights are part of a professional security installation that I would not be allowed to tamper with even if I wanted to.

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