KB6NU's Ham Radio Blog

Heathkit Lives!

May 19, 2003 By 5 Comments

The Heathkit Company has been out of business for quite a while now, but many hams are still using Heath gear. As I’ve noted in an earlier blog entry, I recently resurrected a Heathkit keyer, which has been working like a champ ever since. I also have a Heathkit Triple Output DC Power Supply that I use when playing around with circuits.

I guess I’m not the only one still playing with Heathkits, as I just stumbled upon The Heathkit Shop. This website has all kinds of free information including a nice page full of links to information on the Heath Co. and their ham radio gear as well as repair guides for the HW-8 QRP transceiver, HP-23 high voltage power supply, HM-102 HF watt meter, HWA-202 Power Supply, HD-1410 Electronic Keyer, and HW-202 Two Meter Transceiver.

They also sell a few products, including a replacement PC board for the HP-23 power supply, a replacement display board for the SB104, and a coffee mug with the Heathkit logo. They also have just published a new edition of the HW-8 Handbook, which is a compendium of information on the HW-7, HW-8, and HW-9 transceivers. The book has all of the factory service updates as well as articles on troubleshooting and modifying these rigs.

All in all, it’s a very cool site.

The Slinky Antenna

May 18, 2003 By Dan KB6NU 15 Comments

I used to work for Jon Titus, KZ1G, when he was editor of Test&Measurement World magazine. In addition to being a fine editor, he is the developer of the Mark-8 Minicomputer, which some folks consider to be the first personal computer. He published an article on how to build this computer in the July 1974 issue of Radio-Electronics.

In addition to being a personal computer pioneer, he’s also been a ham radio operator for a long time. At one point, he acquired the patent from the inventor of the Slinky antenna and sold them for a number of years. The patent has since expired, but he still owns the trademark.

I found out about this one day while we were talking about antennas. He was so enthusiastic about the antenna, I said that I’d have to try it for myself. He said that even though he no longer sold the antenna, he thought he still had some of the parts, and that he’d look for them when he got home. A couple weeks later, a package arrived containing two Slinkies, a center insulator, two aluminum clips, and an instruction sheet.

The Slinky dipole antenna, for those unfamiliar with it, uses two Slinky coils instead of wire for the dipole elements. The Slinkies used for the antenna have a bigger diameter than the Slinky toys. This allows you to use fewer turns than if you used the Slinky toys for your antenna. Jon had these coils specially made.

When stretched, the Slinkies form are helical coils. To keep the coils horizontal, you must string a rope through the Slinkies and attach the rope to the antenna suports. I use a pulley attached to my house as one antenna support and a tree branch for the other.

The length of a dipole made with Slinkies as the elements is much shorter than a dipole made simply of wire. In fact, the instructions recommmend that the overall length of the antenna be no more than a quarter wavelength and can be much shorter. You tune the antenna by shorting out a number of coil windings with the aluminum clips.

A Long Time Coming
I hate to admit this, but it took me years to actually build the antenna. What finally prompted me to do so was that our club set up a multi-op station to work the Michigan QSO Party. I figured that the Slinky would be easy to set up and tune, and beause it’s a short dipole, could fit in a small space if need be.

As it turned out, it was all of that. At first, we decided not to use the antenna. Our host had erected an 80m bazooka antenna, and one of the other guys had brought a multi-band trap dipole. Because we only planned to operate two transmitters, we figured that we’d use a tuner to load up the bazooka on 40m, and use the trap dipole on the higher bands.

As it turned out, however, we weren’t able to get a good match on 40. So, we scrambled and put up the Slinky, tuning it to 40m.

At first, we thought there was something wrong with the antenna. While Tom and I struggled to erect the thing, Sam was reading the SWR with my antenna analyzer. At one point, Sam said, “The SWR looks pretty good now,but it’s jumping around.” I asked myself what could be wrong– bad solder joints, bad coax?

I went downstairs to see for myself. The measurements were indeed jumping around, but as I puzzled over this, I soon noticed that the SWR jumped whenever the operator of station #1 began sending. What we were reading was not a high SWR, but rather RF being emitted by the first transmitter!

After solving that little teaser, we hooked it up to the Drake Twins we were using on 40, and it worked solidly, if not spectacularly for the rest of the day. When we decided to pack it in, it took us only 15 minutes to take it down.

Last weekend, I strung it between two trees in my front yard so that a friend and I could work two transmitters in the Fists Spring Sprint. Despite being only 15 feet off the ground, it worked well despite poor band conditions.

The next day, I took it down and put it up in my backyard, tuning it to 30m instead of 40m. I’m working almost everything I can hear, and getting good signal reports in the process.

One thing I notice about the antenna is that it doesn’t like being wet. The SWR goes from about 1.1:1 to almost 1.4:1 when it rains. Maybe that has something to do with the supporting rope.

Despite it working so well on 30, I think I’m going to put it back on 40. There just isn’t enough activity on 30 for my taste. More about 30m later.

Links
Here are some links describing the Slinky Antenna and variations on the theme:

The RigRunner and Anderson PowerPoles

May 5, 2003 By Dan KB6NU 1 Comment

I finally broke down and bought the RigRunner/PowerPole Starter Package from PowerWerx. The RigRunner is simply a distribution panel for the 12V power that runs all of the solid state devices in your shack.

I bought the Model 4008, which includes an input connector and eight connectors for your rigs. Each of the connectors is an Anderson PowerPole connector. Each is separately fused, using automotive style fuses for ease of use and widespread availability. There is also a small circuit that measures the input voltage and three lights that note whether the voltage is normal, overvoltage, or undervoltage.

The RigRunner is a great design and well-made, but gives the impression that it is overpriced. It is, after all, just a patch panel. You could, of course, build it yourself, but that takes time. So, the question is how much your time’s worth.

Unfortunately, the documentation provided by the manufacturer is not really very good. I could not find any instructions on how to crimp the contacts and insert them into the housings. Unfortunately the Anderson website was not much help, either.

I ended up criming the contacts with a cheap electrical crimper, and in doing so deformed the contact enough so that it was difficult to insert all the way into the housing. After much cajoling, I did manage to force it all the way in, but it wasn’t pretty. I think I’m going to go buy the right crimper. That will be another ten bucks.

I wish I’d read the assembly instructions on the Wake County RACES/ARES website. It would have saved me a lot of grief.

In the end, though, I’ll have a versatile system capable of supply the proper voltage to both my HF rig and my VHF rig as well as any other accessories in the shack. Not only will it make setup and teardown easier, but it will also give me the added reassurance that each of the lines is fuse-protected.

UPDATE 3/12/12: I did eventually purchase a Gardner-Bender crimper similar to the one that’s referenced on the Wake County RACES/ARES website. I think I paid about ten bucks for it. It has one position to actually make the crimp and a second position to make the terminal barrel round again. It works just fine.

I have since purchased the Tri-Crimp crimper sold by PowerWerx. It costs more ($40), but it was designed specifically to crimp PowerPole terminals, and when used properly, produces a perfect crimp. I also purchased the insertion/extraction tool. It works OK, but it’s probably not worth the money. A small screwdriver with a fine blade works just as well, if you ask me.

Those Wacky Japanese Hams

April 28, 2003 By Leave a Comment

As I sometimes do, I fire up the rig for a while before getting down to work. I wasn’t expecting much as conditions on 20m have been very poor lately. You can imagine how surprised I was to hear a bunch of stations between 14050 and 14055 working some kind of contest!

I ran up to my office to see if I could find any information on the contest, but none of the usual suspects had any data on it. So, I went back down to the shack to just listen and figure out the exchange. After I’d done that, I tried calling a few stations, but none of them could hear me, even those coming in at S3+.

Actually, I think a couple of them did hear me after I bumped up my power to 100W. They called QRZ?, but I still wasn’t strong enough for them to copy my call. Oh well…

What I want to know, though, is what wacky organization schedules a contest for Monday evening (which it then was in Japan)?

Another Product Idea: The Computer-Controlled Antenna Analyzer

April 24, 2003 By Leave a Comment

There are several antenna analyzers on the market:

While these are good products, there missing one thing–a computer interface. If the MFJ or my Autek analyzer should have either a built-in computer or a computer interface or both. With that interface, you could make automatically tuning antennas. For example, if you were using a Slinky antenna, you could make a device that would allow the analyzer or computer to control how many windings were in the active coil. For a base-loaded antenna, it could automatically adjust the tuning components at the antenna’s base.

For non-tunable antennas, it could automatically plot frequency vs. SWR curves. It could also store this data and you could plot how an antenna system’s SWR changes over time and in conjunction with various weather conditions.

Wouldn’t that be cool??

Contests, Slinky Antennas, and Antenna Analyzers

April 22, 2003 By Leave a Comment

Last weekend, we set up a multi-transmitter station to participate in the Michigan QSO Party. The goal was to have two transmitters operating during the contest, one on 40m and the other on whatever band was open.

One of the antennas we put up was a “Slinky antenna,” so named because it uses two big Slinky coils as the radiating elements. To tune the antenna, you vary the number of windings that are active. You do this by shorting out a number of them on the end of each element.

When we first put it up, we used the tuning chart in the documentation to adjust the length of the antenna and the number of windings to expose. When we measured the standing wave ratio (SWR) with an antenna analyzer, it was about 7:1, not very good even for amateur operation. So, we increased the number of windings on each leg by 5, and the SWR dropped to about 3:1. We let out five more and the SWR dropped to about 1.25:1.

BUT, the guy who was reading the meter said the readings were jumping all over the place.

Hmmmm, I thought. What could be wrong? Did I perhaps not solder something correctly? Is the coax bad? Is the antenna inherently unstable?

I went down into the basement to see for myself, and sure enough, the readings would settle down and then bounce around for a while. It took me a couple of minutes to figure out that the problem was that while we were making these measurements, our second transmitter was busy trying to make contacts on another band. What we were reading as a reflection was actually RF being output by our other transmitter!

After we all got a good laugh out of that, we hooked it up to one of the transceivers and it worked pretty well for the remainder of the contest.

URLs from the April 2003 QST Classifieds

April 8, 2003 By Leave a Comment

Last night, I found myself paging throught the April QST classifieds. Here are a few of the URLs I found interesting:

www.anthonywelsh.com: Sells an odd assortment of stuff, including keys and paddles, capacitors, tubes, and oil paintings. Yes, I said oil paintings.
www.digifield.com: Sells the Digi-Field Field Strength Meter. The meter has a digital readout, and they claim a bandwidth of DC to 12 GHz, but it seems kind of expensive at $219.
recradioswap.com: This seems to be yet another ham radio classifieds website. Unfortunately, there’s hardly anything for sale here. The only categories with more than 2 or 3 items are the accessories categories, and these have mostly old Motorola stuff in them.
www.TMastCo.com: I was hoping to find a source of aluminum tubing for antenna projects. Instead, the main product of this company is a set of military surplus masting tubes. They also sell telescoping fiberglass poles that look like a decent deal. A 22-ft., heavy duty (whatever that means) pole is $45.
www.radiofinder.com: Joel Thurtell, K8PSV is the Radio Finder, and this site is devoted to his business of buying and selling boat anchors. It’s a very interesting site.
www.callbook.com: Apparently a German company has purchased the rights to produce the callbook, and they plan to produce both a CD version and a printed version. The CD is already shipping; the printed version is to be available May 2003.
www.powerwerx.com: PowerWerx sells a bunch of accessory-type stuff, but specializes in kits consisting of RigRunner, 12V distribution panels and the Anderson PowerPole connectors and power cable to go along with them. If you buy the kit, you save a few bucks over the piece prices.
www.edromney.com: Ed Romney self-publishes a bunch of books on camera repair and a single volume on antique radio repair. It’s a bit hard to find on the website, and imho, kind of expensive at $35 a pop.

Macho CW

April 6, 2003 By Dan KB6NU Leave a Comment

A couple of days ago, I had a contact that I could only describe as “macho CW.” We were both using keyers at 20+ wpm, and it was clear that neither of us was copying the other 100%, but neither of us would ask the other to slow down. The one doing that would be, of course, admitting that the other was the better operator.

Something similar happens in the cycling world. Sometimes two or more riders will be in a pack, cranking along at a pace that none of them can really sustain, but none of them wants to be the wimp that asks the group to slow down. What usually happens in that case is that the slower riders eventually just give up as they tire out.

Since operating CW isn’t such a physically tiring activity, what usually happens is that one of the operators says something like, “SRI OM, MUST QRT NW” or “XYL CALLING ME TO DINNER.” It’s a way of saving face. The contact ends with neither operator admitting defeat.

This is, of course, poor operating practice, and I won’t try to justify my behavior, except to say, that if it were an emergency situation, I doubt that I would have been so stupid. If the communication definitely had to be made, I would not have been too proud to ask the other op to QRS. At least I think so….

Antenna FUBAR Again

April 5, 2003 By 5X7JD Leave a Comment

Last night we had pouring rain, followed by some freezing rain. Looking out the kitchen window while making breakfast, I could see a coating of ice on both the coax and my 20m ground plane antenna.

After breakfast, I went down to the shack to work a little CW, I found the SWR to be way up again, measuring about 1.7:1 at 14050 kHz. I went outside and wiped off the coax, but that didn’t seem to do anything.

I’ve been waiting for it to warm up and for the ice to melt, but the temperature’s been hovering around freezing all morning, and I’m not sure it’s going to get much higher today.

Maybe it’s time to replace that coax. It is, after all, a piece of coax that I’ve had laying around here for years. I can’t imagine that it’s a problem with the antenna itself, but I suppose that’s a possibility.

Update: 4/6/2003, 1130am
Well, this morning, the antenna was back to normal. That coating of ice must have been what was causing the high SWR. As I’ve said in the past, I’m no antenna genius, so I don’t have a clue as to why this should have been so. Anyone have an idea?

Unfortunately, the band conditions this morning aren’t all that hot, and there are a couple of contests, including the Polish DX contest and the QCWA QSO Party, on 20m this morning, so I haven’t been too successful making contacts. I did call one of the Polish stations, and he heard me, but I wasn’t strong enough for a solid contact.

AC6V’s FM101x: A Book for the New Tech

April 3, 2003 By 1 Comment

Back in the old days, the first license most amateurs received was the Novice license. When new hams got their Novice licenses, they put up an 80m or 40m dipole, fired up the transmitter, connected their key, and started pounding out CQ. There were plenty of books that not only showed them how to do that, but also how to make CW contacts.

Nowadays, of course, the first license most hams get is the Technician license, and their first rig is an HT that they’ll use to talk over the local repeater. Most of these radios already have an antenna, so getting on the air isn’t a problem. What to do when you get on the air can be, though.

That’s why Rod Dinkins, AC6V (of www.ac6v.com fame) wrote AC6V’s FM101x: A Guide to Your First VHF/UHF Radio and Using FM Repeaters. In this book, Rod, who was a technical writer for Hewlett Packard for more than 20 years, clearly explains not only how to choose and use a radio, but also what to do with it once you have it.

The book includes chapters on:

Your First FM Radio. This chapter will help you purchase your first FM radio. Discusses advantages of Handi-Talkies vs Mobiles, antennas, batteries, features to consider. All mode radios and multi-banders are discussed. Mobile installation, Mobile Antennas, DC power supplies, Noise Abatement, Mobile Power considerations, Coax Considerations, and VSWR checks.

Operating Simplex. This chapter discusses simplex operation, or operation without a repeater. It describes the range you can expect, antennas, cross polarization, and protocol. Includes a complete list of simplex frequencies from 2 meters thru 1.2 GHz including the recommended National Calling frequencies.

How Repeaters Work. This chapter tells you everything you need to know about how a repeater works, and includes a simplified pictorial of a repeater. This chapter covers simplex, half duplex, and full duplex operation. It explains offsets, splits, input and output frequencies and lists the standard offsets for USA repeaters – 10 meters thru 2.4 GHz. Thoroughly covered are CTCSS, PL, subaudible tones, tone squelch, DCS, CTCS, tone burst, DTMF, and other repeater beeps and bebops.

Programming a Rig. This chapter walks you through the process of programming your radio. It shows you how to make a cheat sheet and use programming cables.

Antennas, Power Sources, VSWR, and DeciBels. This chapter explains why the rubber duck antenna is a mediocre antenna at best and describes more effective antennas. such as the quarter-wave, half-wave, ¾- wave, and 5/8-wave antennas. It also cover Yagis, and J-Poles and gives numerous tips for building your own antennas. The concepts of VSWR, and dB are covered in an accessible, non-technical way. The power sources section discusses the different types of batteries, including sealed lead acid (SLA), Lithium, NiCad, and NiMH batteries.

Using Repeaters. This chapter tells you how to find repeaters, including how to use repeater guides on the internet. Then, once you’ve found a repeater, it gives you a complete rundown on repeater protocol, soliciting a conversation, asking for information, jargon heard, radio checks and signal reports, what to say, breaking in, multiple conversations – rotations, nets, roll calls and demos, autopatching. Also listed is a complete listing of 2 Meter repeater pairs, packet simplex, and voice simplex frequencies.

Phonetics, Q-Signals, and Callsigns. Confused by Q-signals? This chapter not only explains the Q-signals used on repeaters, but also the phonetics you’ll hear.

Funny Repeater Sounds. Repeaters produce a myriad of strange noises, and helps you determine what these sounds mean, including path noise, distortions, alternator whine, ignition noise, capturing, Morse characters, hum, over and under deviation, kerchunk, desense, CB talk, i.e. ten codes.

Cops and Jammers. This chapter will help you determine when and when not to play repeater cop and how to deal with jammers and interlopers.

Inside A Repeater. This chapter includes detailed block diagrams of the elements of a repeater and discusses in plain language how duplexers, limiters, discriminators, deviation, bandwidth, channel spacing, modulation index, and FM modulation work.

Interconnecting Repeaters. This is one of the most exciting new ways to use a repeater. Discusses how amateurs are using IRLP, ILINK, and crossband repeating to extend the range of their systems.

Glossary and Jargon. This chapter includes 16 pages of terms, slang, and repeater speak.

While not for the experienced operator, this book is quite comprehensive and is sure to help the most intimidated get on the air successfully. It really is a great book for the Technician who’s wondering, “Now, what do I do?”

You can buy this book on QTB.Com. Just click here.

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