On 11/17/2022 1:13 PM, Jeff DePolo WN3A wrote:
Everybody keeps talking about mods to the GE voter. E&M signalling is
standard on them, even the old grey ones. So voter tone isn't needed if
you have a relay closure or other good switching.
Mods are still required to use a GE voter without status tone if you want to do it right. For starters, you'll want to get rid of the 1950 notch filters on the receiver cards and the audio module to clean up the audio response. Disabling the 1950 detector is also a good idea to prevent voice falsing, as well as disabling the channel failure detection. And you'll want to configure for no AGC. The stock E&M input (active LOW) input requires 12 to 17 volts on the newer black/SMD cards (wider range on the old cards), so not directly compatible with TTL or the logic from many radios/receivers. So, yeah, at the basic level the functionality is there to use E&M instead of status tone, but some additional work, level translation, and other details still need to be addressed - it's not "COR-ready" per se.
--- Jeff WN3A
Ok, killing the 1950 notch is a good idea, but to me that's a separate issue. I've never run across voice falsing on them though, plus I would not worry about disabling channel fail. It doens't affect E&M directly, unless someone decides to dump a continuous tone, probably also squelch noise. That will fail any channel involved.
As to voltage levels, well, it all depends on what you're using to key it. I was successful with some old HT90's as link rx's, but the GE MPA's I'm using right now are too low, and I think inverse, so I found some little relay drivers laying around that did the deed. But it works perfectly, no changes to the voter or the cards at all.
Could there be a difference in terminology here? To me, making mods to something like this means actually changing parts, or board traces, or something like that. Eliminating the notch filter would be a mod. Adding a relay driver to either the link rx's or the back of the voter, or a separate box, whatever, to me isn't a mod, it's part of the interfacing.
