Stingray Marine Transceiver

Its been a while since the last post, a lot has happened. It looks like WordPress has changed quite a bit too!

At the Ballarat Hamfest recently, I picked up an old Marine transceiver for a princely sum of $10. What I liked about it was the cast housing and it seemed to have a bit of waterproofing which I guess is no surprise. It was made in Sydney by Findlay Communications. Australia used to have a lot of radio manufacturers once, what a shame most have now disappeared.

I had no idea what condition it was in, I could not go wrong at $10. After getting it home and prising the covers off (they were sealed with a silicone type stuff), it looked pretty good inside. It is crystal controlled with a claimed power output of 120 Watts. Frequency coverage is stated at 2-13 MHz, AM/USB with 10 channels.

Power was applied and a big fat nothing. It didn’t take long to see that the speaker wire was disconnected. After reconnecting, it sprung to life and crackled when a bit of wire was put in the BNC socket.

When the antenna was connected it seemed good and a signal generator confirmed that the sensitivity was good. Next thing was to try transmit. PTT resulted in a soft click from the relay but no change from receive to transmit. Inspection of the relay showed that it had sticky stuff on the armature. Removal of this fixed the problem and it went into transmit on PTT. No output though 😦

I posted a request for a manual on the local forum and was surprised that a guy, John in WA had a manual. It didn’t take long to find a burned out resistor in the PA from the output transformer to ground. The resistor was replaced and power output looked respectable. Something like 50 Watts in AM mode and more in SSB mode.

Crystals are petty expensive if you can get them these days, so I went about replacing the crystal oscillators with an Si5351a controlled by an Arduino. My main aim was to have a boat anchor radio for 160m AM and something on 30m SSB. The radio looked very tatty so I gave it a paint job and made some side grab handles for it out of 5mm thick Aluminium

It all worked out well, and I had the first call on it today to a VK2 on 30m. Good signals and the radio sounded pretty good. The radio has retained a few marine channels and I have added 1.825 MHz AM and 10.125 MHz USB. There is another output on the Si5351a clock generator, so I might add a 20 metre frequency. It would be easy to add a rotary encoder and display but that would probably be over capitalising the radio 🙂 The paint cost more than the radio.

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8 Responses to Stingray Marine Transceiver

  1. Paul Taylor says:

    That’s a bargain that I would have found hard to walk past. $10 for an HF AM and SSB transceiver, amazing. Marine transceivers are solidly built too, so it should have a robust PA with protection. You must need a decent 13.8v power supply.
    I guess the rigs filtering, particularly the LPFs, are arranged to cover the full 18MHz of spectrum.
    I like the idea of leaving it channelised, if you put 7125 in you should get the occasional AM contact there.
    73 Paul VK3HN.

    • vk3yy says:

      OK on 7124kHz, that sounds like the next one to put in. I was attracted the solid cast case! It draws about 20 Amps on transmit, and that caused some smoking on the workshop power supply during a sustained transmit and tune. The power supply still works though.

  2. Mikael Elson says:

    A very nice projekt and l have a closer look at it
    73 and GL sm7ipf

  3. nemo1956 says:

    Hi there. Your find at the rally was really good. Sadly we don’t get such a meting here in Thailand.
    Sounds like your going to have a lot of fun with this.
    I like getting old and disused equipment and modifying them for ham radio use for myself.
    I’m currently looking for something for the 10m band SSB.

    Hope one day we can have a chat on the airwaves.

    73’s. And good luck with your project.
    Paul. De​HS0ZLQ /G0MIH.

    • vk3yy says:

      Thanks Paul, yes it’s been fun. 10m propagation has been very good over the last week, good luck with your 10m project!

      • nemo1956 says:

        Yes 10m it going really well over here now. Most days I can hear lots of signals but only on receive.
        De HS0ZLQ /G0MIH.

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