Batboard

Posted: **Fri Mar 03, 2017 6:07 am**

I'm looking at combining audio from two XTLs into a Pyramid SVR-200. I only need to transmit on Radio 1, but want audio from both XTLs coming across the VRS. I have the Pyramid Smart Cables and I want to adapt it at the 9 pin Serial end. I'm thinking of making some sort of a junction box and from there that would feed into the single SVR-200 installed.

This is what I'm thinking:

Code: Select all

Pin 1 Ground. Only one needed, disable pin from radio 2 cable. 
Pin 2 Mobile transmit audio. Radio 1 only, disable pin from radio 2 cable. 
Pin 3 Enable / disable VRS -- disable both; using switch
Pin 4 Mobile PTT output. To Radio 1 only, disable pin from radio 2 cable. 
Pin 5 12v input. Only one needed, disable pin from radio 2 cable. 
Pin 6 Mobile receive audio. Combine both pins from radios 1 & 2.
Pin 7 Mobile COR Detect. Combine both pins from radios 1 & 2.
Pin 8 Local mic audio. Not needed, disable both pins from radios 1 & 2.
Pin 9 On Air Detect. Not needed, disable both pins from radios 1 & 2.

I believe this should all work but I need to keep the lines on Pins 6&7 isolated, yes? How would I achieve that??

Posted: **Thu Mar 09, 2017 3:21 am**

Use a 1uF capacitor on the audio lines, and a diode on the COR lines. Gallenium & Selenium diodes only drop about .3-.4 volts, so the SVR should still see it as a valid COR.

Posted: **Thu Mar 09, 2017 8:05 am**

Thank you for your response. I have two follow up questions:
Any 1uF capacitor work or does it need to be within a certain voltage?
I understand the diode concept but am still unsure which one to pick up. Do you have a link to the proper one I could purchase one online from? Amazon or something? I'd really appreciate it.

Posted: **Fri Mar 10, 2017 3:46 am**

A standard electrolytic rated for 25 volts is fine. You could go with a mylar type & not worry about polarity, as well. For the diode, try any standard silicon diode first, they are cheap & plentiful and drop about .7 volts.

I had said gallium above, I meant germanium diode, if you need to try a .3v drop. Just google them, plenty of options.

Posted: **Fri Mar 10, 2017 5:33 am**

Thanks for the info.

Batboard

Two XTLs with a SVR-200

Two XTLs with a SVR-200

Re: Two XTLs with a SVR-200

Re: Two XTLs with a SVR-200

Re: Two XTLs with a SVR-200

Re: Two XTLs with a SVR-200