The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

Hi everybody, I've got an old Realistic TRC-467 im modding for a friend and it has no PA. Could anyone tell me what my options are for doing a talkback mod on it?

thanks!

I got the same problem.....a magnum 257, and nobody seems to know how to do this, except for adding a UTB board by RF Limited.

There's a way but I think that people want to keep it a secret. Here's how I did it.

Connect the negative terminal of your speaker to the RX pin on the inside of the mic jack with a resistor in line. I used a 100 ohm because I like my talkback a little loud but i think 150 will be better for most applications.

I've been told an easier way is to hook a resistor up between your RX pin and ground pin on the mic jack. A third way is to run a wire with a resistor between your speaker's negative terminal and the ground on your radio which didn't work for the particular radio i was trying it on.

Good luck with it!

Shadow, your for sure that will work? I will give this a try, and post my results. Thanks

Shadow wrote:There's a way but I think that people want to keep it a secret. Here's how I did it.

Connect the negative terminal of your speaker to the RX pin on the inside of the mic jack with a resistor in line. I used a 100 ohm because I like my talkback a little loud but i think 150 will be better for most applications.

I've been told an easier way is to hook a resistor up between your RX pin and ground pin on the mic jack. A third way is to run a wire with a resistor between your speaker's negative terminal and the ground on your radio which didn't work for the particular radio i was trying it on.

Good luck with it!

Man, I tried all those way, and nothing works. I just can't figure this out, lol. I guess I'll have to get one of those daggum utb boards, and put it in there.

Shadow wrote:Hi everybody, I've got an old Realistic TRC-467 im modding for a friend and it has no PA. Could anyone tell me what my options are for doing a talkback mod on it?

thanks!

Do you want variable talk back in that thing?

dodgem250@somd.net

The nice thing about the UTB by magnum is they are totally independant and sound really nice, well worth installing, I go through lots of them.

Why bother wasting time with talk back, try putting a variable output control or something usefull like that.I had t/b on my Ranger 158EDX and disabled it .
Bob

The way I did this was finding the current limiting resistor for the TX led and solder a wire BEFORE the resistor, then solder the wire to the coil of a small 5-12vdc relay. The other relay coil wire solders to the negative lead of the battery connector.

Next, clip your speaker's negative lead about half way and solder the end from the board to the normally closed pin of the relay. Solder the other cut wire (connected to the speaker) to the neutral section of the relay. Now solder a resistor (27-47ohm or more) to the normally open pin of the relay (this determines your talkback volume) OR you can use a variable resistor for adjustable talkback level. Now solder a 33-47uf polarized cap in series with the resistor to the case ground (not board ground). Now when in RX mode the speaker is connected to the amp, when keyed up, you should hear yourself transmitting, if not check your connections.

This will not work for some radios, however it worked fine for me. If you have no TX LED, you can find another voltage source.

Shadow wrote:Hi everybody, I've got an old Realistic TRC-467 im modding for a friend and it has no PA. Could anyone tell me what my options are for doing a talkback mod on it?

thanks!

150 ohm resistor to the ground of the external speaker jack solder it to ground of the chassis, if you want on-off, put a spst sub-mini inline, if you want variable, I can do that too

In the TR 467, The speaker is already grounded, it isn't a floating ground. running a resisitor to chassis ground will do nothing in this specific radio.