AB4UG Radioblog

RFI in the house

Finally had a chance to connect the antenna up to the radio using the coax running through the conduit from the garage side of the house into the shack. Up until now, most of the operating (what little of it there’s been) has been out in the back yard with the radio connected directly to the antenna.

This weekend, I thought I’d give the ARRL November Sweepstakes (Phone) contest a try. After making a 40m contact Sunday morning, I noticed the network had gone down. Discovered the GFCI breaker for the circuit that our service provider’s ONT box is on had tripped. Not entirely positive it was because of me operating on 40m, because I had made a handful of 40m contacts on Saturday without any problems (that we noticed anyway). Seems likely to be an RFI issue though since the network was up just prior to my QSO.

Reset the breaker, got the network back up, and switched over to 20m but then the wife spotted one of her edge lit acrylic signs flickering on and off while I was making another contact and basically turning it into an “On the Air” sign.

Not wanting to risk messing up anything else in the house by overloading them with RF, I wrapped up the ARRL November Sweepstakes contest with 12 contacts in the log and 240 points with most of my contacts from Saturday evening on 40m (40m opens up pretty nicely out to the West coast in the evenings from here).

I’ve had the antenna up a handful of times since we’ve been in the house, but most of my operating has been outside, so any RF-induced problems there might have been in the house have generally gone unnoticed (except maybe for the time the Nest thermostat died). I’m pretty sure the issue is because most of the antenna lays on top of the roof and on the side where most of the wiring is (electrical service entrance, breaker panel, network router, AC unit, etc). Running 100W is probably causing a lot of RF to be coupled into the house wiring.

So it looks like I’ll have to work on changing the antenna situation. Moving the antenna and mast to the fence on the other side of the house would probably get the antenna far enough away to solve most of problem, but then I wouldn’t be able to use the coax running through the conduit without making the coax run a whole lot longer. The mast would also be on the street side of the house making it even more visible when set up. I could also order a ton of ferrite chokes to put on pretty much any current carrying wire in the house (that could get pretty expensive). I guess I could also take my operations portable and head out into the field or a park.

A collection of Handbooks

A collection of ARRL Handbooks from 1944, 1950, 1971, 1974, 1979, 1980, 1993, 2005, 2012, 2014

Somewhere along the way, I apparently thought it would be cool to have at least one ARRL Handbook from each decade. Over the past few years, I’ve managed to acquire a few Handbooks toward that goal. Some I found at hamfests, some through the annual ARRL Auction, and some through SK estates.

The most recent additions were the 1980 and 2005 Handbooks. They came from the collection of one of my ham friends, Willie/WB4SOG (SK), who died recently. Willie was a prominent member of the local amateur radio community, and he’ll be missed by many people. I actually met him several years before I became a ham through his wife who volunteered with the same lab retriever rescue that I did. His friend Bruce/KI4YST brought several boxes of books and QST magazines from Willie’s collection to the club meeting for club members to take. I’m glad to be able to give some of his books a new home in my collection.

Handbooks from the 1920s and 1930s would be a nice addition to the collection. I’m sure I could find them if I looked harder. They’ve shown up in the ARRL Auction in the past, and there’s a 1932 Handbook in this year’s edition of the ARRL auction. Bidding on that Handbook sent the price pretty high early on. Probably plenty of old Handbooks on eBay too.

I haven’t read them all yet, but I’ve looked through a few of them and they give a nice look at how amateur radio has evolved over the past century.

The Handbook I’m planning to get for the 2020s will be the 2023 edition, which will be the 100th edition of the ARRL Handbook.

Speaking of the ARRL Auction, it seems like the interest in older handbooks is a lot higher this year and there’s been a lot more bidding on them than in previous years. Past auctions I think also had more Handbooks up for bid if I recall correctly, so maybe that was a factor.

Another Astatic D-104 microphone

An Astatic D-104 microphone was my final, last-minute purchase from the Shelby Hamfest. We were walking to the gate heading out when I spotted a table I hadn’t visited off to the side and decided to wander over to have a look. The D-104 on the table naturally caught my eye, and decided to grab it.

This one was missing the bottom cover plate, and the microphone connector was removed. Looked like there might have been some re-wiring done at some point and two of the wires from the cord are unconnected, unlike my other D-104 microphone. The electrical tape on the wires connecting the microphone element suggests that maybe it was replaced at some point as well.

At least there’s no rotting foam in this one. The microphone element housing is also a little different from my other one. This one is basically just a ring with some bits of foam supporting the microphone element while my other D-104 is more case-like.

I’ll have to see what I can do about finding or making a new cover plate for this microphone.

Back to hamfests: Shelby 2021

Made a trip out to our first hamfest in quite a while (last one was back in 2020).

We made the road trip out to the Shelby Hamfest for the first time. It’s one I had been wanting to get to for quite a while now, but it happens the same weekend as Dragon*Con so I never made it until this year.

We drove up Friday afternoon, and Saturday was the only day we spent at Shelby. Got there bright and early as the gates were opening, so we were able to get a decent parking spot. Spent the early morning wandering around the boneyard/flea market checking out the early birds that opened up their tables until the indoor stuff opened up. Checked out the indoor people, then spent the rest of the morning exploring the boneyard.

Lots of people out in the flea market area selling the usual range of really nice gear to miscellaneous stuff. Saw at least 3 or 4 people selling some really nice looking Collins radios, ranging from complete sets to single cabinets. I can see why people like to collect Collins gear. They’re really nice looking units. I got a bit drooly looking at them.

Didn’t really have a big shopping list going to the hamfest, but did end up picking up a few things with the goal of putting mobile VHF radios into the cars in mind. In the boneyard, I found a couple of Fluke multimeters for a pretty good price. Seller didn’t know what condition they were in, but I figured for $10, they would either be decent workbench instruments or fun projects to work on. Also found a D104 mic missing the bottom plate and connector for pretty cheap so I grabbed that too. A few other miscellaneous tool type items rounded out the shopping day at the hamfest. Didn’t see too many Morse code keys, but there was one table that had a selection of older Vibroplex bugs that I was kind of tempted by.

The crowd seemed to be a lot lighter than I expected, even during the middle of the morning and early afternoon. There were a lot of cars in the parking are by the time we left but it didn’t seem that crowded while we were there. I suppose the size of the hamfest helps spread everybody out. Had some fun random encounters with a few other hams that we new, and a nice conversation with Bill Morine/N2COP, ARRL Roanoke Division Vice-Director.

I was too busy wandering around checking things out and trying to decide if I “needed” it or not to get any pictures of the hamfest, but Connie got this early morning-ish photo of the boneyard off in the background.

Early morning at the Shelby Hamfest boneyard

Tempo S1 FM transceiver

I can finally get around to some of the things that have been sitting in boxes in the garage for the last year or so.

Here we have a Tempo S1 handheld 2m FM transceiver that’s had some obvious modifications done to it. The battery pack was replaced with a car power adapter, the original telescoping antenna was replaced with a BNC connector and, based on photos of other Tempo S1 units I’ve seen online, the earphone and antenna jacks have been replaced.

Tempo S1 handheld FM transceiver control panel — Tempo S1 handheld FM transceiver

Frequency selection is done by setting the thumb wheel switches to the desired frequency. A slide switch for the 1 kHz place lets you select 0 or 5 kHz, giving the radio 5 kHz tuning steps. In the photo, the radio is currently tuned for 145.690 MHz. To get 145.695, you’d slide the switch over to the +5k position.

Getting inside the unit is a simple matter of undoing 4 somewhat rusty screws. The back lifts off to reveal the radio guts and the battery compartment where the car power adapter was wired in.

Tempo S1 handheld FM transceiver power connection

According to the manual, an 8 cell NiCad battery pack providing 9.6V fit into that space. Charging the battery was done by plugging an external charger into the 1/8″ jack next to the offset selector switch.

The radio guts consist of two circuit boards. One appears to handle the RF side of things, while the other one looks like it handles the controls. It’s quite the nest of wires inside.

Tempo S1 handheld FM transceiver circuit board

There’s a single IC on the board with a sticker labeled NIS-103, which I’m guessing might handle generating DTMF tones from the keypad on the front. A few wires have been soldered directly to the legs of the IC so whatever it is, removing it won’t be easy to do.

Tempo S1 handheld FM transceiver integrated circuit

An inspection of the components on the boards didn’t reveal anything that was obviously problematic. Lots of tantalum capacitors and a few electrolytic caps, but they looked fine.

Didn’t have 9V handy to connect to the power leads but I did have a 12V battery pack, so I connected that to the radio and turned it on. The radio came alive with static, which seemed like a good sign. Didn’t try anything else with the radio. I’ll work on making up a suitable connector so I can attach a 9V battery or find a suitable replacement battery pack for future experimenting.

Given the radio doesn’t have any CTCSS capability, it might be of limited use with repeaters these days unless they don’t use CTCSS tones. Still should be useful for simplex communications though.