Astatic D-104 microphone

I’ve always liked the aesthetic of the D-104 microphones, so when I came across someone selling a couple of them at the local flea market a few months ago, I bought one of them.

  • Astatic D-104 microphone
    Astatic D-104 microphone
  • Astatic D-104 microphone
    Astatic D-104 microphone
Astatic D-104 microphone

None of my radios uses a 4-pin microphone connector, so I haven’t tried the D-104 out yet. I’ll need to make an adapter for it first.

In the meantime, time to take a look inside. I’ve read online that there are a number of modifications that can be made to the D-104, so I wanted to see what the state of this one was.

Undoing three screws allows the bottom base plate to be removed, revealing a terminal strip, the amplifier board, a volume potentiometer, and a battery. The battery was pretty dead (~4V on the DMM) but fortunately it hadn’t leaked.

  • Astatic D-104 microphone circuitry
    Astatic D-104 microphone circuitry
  • Astatic D-104 microphone circuitry
    Astatic D-104 microphone circuitry
  • Astatic D-104 microphone circuitry
    Astatic D-104 microphone circuitry
  • Astatic D-104 microphone circuitry
    Astatic D-104 microphone circuitry
Astatic D-104 circuitry in the base

I don’t know what the innards of a D-104 are supposed to look like, but this seemed pretty stock to me.

The back plate of the microphone head was removed by undoing 4 screws. The microphone element takes up most of the space inside the head. Foam attached to the back plate helps keep the microphone element in place. The foam here was pretty badly deteriorated.

  • Astatic D-104 microphone element
    Astatic D-104 microphone element
  • Astatic D-104 microphone element
    Astatic D-104 microphone element
Inside the head of the D-104 microphone.

The connections on the microphone element look pretty messy because of the rotted foam, so I might need to replace it.

A connection diagram is conveniently attached to the base plate.

Astatic D-104 schematic
Astatic D-104 schematic

I think this will be a fun microphone to use with the radio once I get a proper connection made up (and maybe a new microphone element).

Atlas 210X HF radio

One of the items in the KB4NNM (SK) collection that was donated to the club earlier this year was an Atlas 210X 5-band HF radio mounted in a 220-CS AC console. The console allows the radio to be operated off mains power, provides a speaker and VOX capabilities.

Atlas 210X mounted in a 220-CS AC console
Atlas 210X mounted in a 220-CS AC console

It’s a pretty nice looking setup. Until I did a bit of research on the radio, I didn’t realize that the radio and console were separate items. Turns out, the radio just slides into the console, and connects using some 1/4″ plugs and a banana jack-like connector for the antenna.

Atlas 210X removed from the console
Atlas 210X removed from the console

Sounds like the radio works, although the speaker produces a buzzing noise (60Hz hum I think) even when the radio’s AF gain is turned all the way down. Turning some of the dials and switches produces some static-y noises, so it sounds like those will need some cleaning. Haven’t had a look inside the radio yet. That will be later.

This seems like it might be a nice radio to use in the club room.

Field Day 2020

Thanks to the COVID-19 pandemic, Field Day was a bit different this year. No big gatherings, and many of the public spaces that normally hosted Field Day this year were closed or only permitted small groups. With some modified rules for Field Day this year, there were a lot of Class D stations (commercial power) on the bands this year.

We got our back yard Field Day set up (1D SC) and invited neighbours over. Set out a few items for people to check out, and got the radio fired up. Had a few of our nearby neighbours over, and another person stopped by with her grandkids later in the afternoon.

  • WWII era radios on display
  • Ham, the terra cotta radio pig
  • Radio kits
  • Dipole support

We were able to show off radio operating during Field Day, talk about some of the things amateur radio operators do on the radio, shared radio stories, and show off radio related paraphernalia like QSL cards, boat anchors, Morse Code keys and some of the kits I’ve put together.

Plenty of activity on 10m today, which was where I spent most of the afternoon in seek and pounce mode. The pileups were thick and a bit challenging to get through, but I was able to make it through a few of them. 10m started to slow down as the afternoon went on, so I dropped down to 20m where there was even more activity. Worked a few stations there and popped back up to 10m to get one of our newly minted Tech friends her first HF QSO. Then it was back down to 20m for a few more contacts until the mosquitoes got bad enough to make me call it a day. I ended up with 22 QSOs in the log, with the last few getting out to the west coast.

Even though this year wasn’t a typical Field Day, it was still a good radio weekend.

More boat anchors

Every now and then, as president of the local amateur radio club, I’ll get an email from someone looking to donate radio gear to the club so that it can be put to use by someone. I usually arrange for myself or one of the other club members to go pick up the gear, and we’ll check it out. We’re always appreciative of donations like this and usually the equipment ends up with new hams starting out in the hobby.

The most recent email I received a few days ago didn’t say what kind of equipment it was and when I arrived to pick up the gear, I was quite surprised. The equipment donated by the family turned out to be not amateur radio gear, but two sets of old surplus US Navy communications equipment dating back to 1944 and 1945. Pretty cool museum pieces.

There were also a couple of old CB radios and some mag mount antennas but compared to the main haul, they seemed somewhat incidental.

Surplus US Navy communications equipment
Some unexpected equipment

On the outside they’re not in the greatest shape, and appear to have been sitting around in storage for at least a few decades. Most of the pieces had lots of built up dirt and dust, and a lot of flaking paint. And they were heavy.

TCS-13 radio transmitting and receiving equipment
TCS-13 transmitter (top) and receiver (bottom)
CIH-52245-A radio transmitter
CIH-52245-A radio transmitter
CIH-46159-A radio receiver
CIH-46159-A radio receiver

Each set has a transmitter, receiver, power unit, antenna loading coil, and remote control unit. All of them look like they might have been cannibalized for parts at some point.

CML-47205 antenna loading coil
CWS-23270 remote control unit
CWS-23270 remote control unit

An instruction manual even came with the collection, luckily enough. Should be helpful with the restoration.

Model TCS-13 instruction book
Model TCS-13 instruction book

The power rectifier units were the heaviest of all the units, and each of them appeared to have had a few parts repurposed from them.

COL-20218 rectifier power unit
COL-20218 rectifier power unit

They’ve definitely seen better days.

I kind of doubt they can be restored to operating condition, but I think at least one set can be cleaned up enough to use as a display piece, maybe for the club room. I’ll have to see if there are any club members interested in restoring boat anchor gear who might want to make a club project out of this. Should be a fun project to work on.

I made a thing