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THE AM BULLETIN BOARD => Technical Forum => Topic started by: KD1SH on December 02, 2025, 11:22:32 AM



Title: G-50 Push-To-Talk.
Post by: KD1SH on December 02, 2025, 11:22:32 AM
   Well, the site's been up and running uninterrupted for a couple of days now; perhaps the dark days are behind us? I certainly hope so. So, while the site is up, I'll take advantage of the opportunity to contribute some fun stuff.
   I've got two Gonset G-50s: My first one, with the metal knobs, bought at Nearfest back in 2018, and my second, with the blue knobs; again, a Nearfest find, but this time in the fall of 2024. A few weeks ago, I slid "Blue" out of its cabinet to look into a modulation problem I'd noted a while back, and discovered, sadly, that one of the decks of the triple-stack T/R rotary switch had broken all to pieces. I'm assuming that it happened during removal or installation into its cabinet.
   What to do? I've got a Gonset G-28, the 10-meter version, that I could use as a parts donor. Or, something I'd thought of in the past but never seriously considered: replacing the rotary switch with an array of relays, for push-to-talk functionality. Okay, great chance to try something new!
   The plan is to replace the original rotary switch with a simpler single-deck switch, mounted right behind the front panel, doing away with the long shaft that turns the rear-mounted switch, and using that switch to simultaneously actuate an array of relays. That way, the original functionality of the front-panel T/R switch can be maintained, while still allowing push-to-talk action via the microphone.
   Fortunately, the interior of the G-50 isn't nearly as densely packed as the Lafayette HA-460, but still, the project required moving some components around, as well as removing the aluminum structure to which the original rotary switch was mounted.
   It's a bit of an endeavor, really, and I wouldn't recommend doing it on a whim; I'm only doing it because the original switch broke. Otherwise, I'd recommend staying with the original T/R operation. Note in the picture that there are 6 relays on my board. Each is double-pole/double-throw, for a total of 12 individual SPDT switches, and I'll be using all of them. When you flip that switch on a G-50, there's a lot going on in there!
It's an ongoing project, and I'll post some more progress soon.


Title: Re: G-50 Push-To-Talk.
Post by: AG5UM on December 02, 2025, 11:33:43 PM
Interesting idea,
 I guess your past banana plugs and knife switches...
 I think you might need some of the old Bell System, Western Electric switching network equipment,
It was vacuum tubes and relays, etc...
Also,
Its always great to see the workbench photos, (I think I actually have more interest in test equipment than radios.)
You have some interesting things there, Cool.
Keep us posted and good luck with your project.

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