Collins 20v2 control electronics

[wx3k]

In the picture below, which I snuck off someone's website, forgive me :-)

Are the control boards along the back vertical edges of the cabinet present in all 20v's models ?

[Mike/W8BAC]

In a word, no. If the transmitter was purchased from Collins with the Day/Night options installed you would have a relay operated 10 DB (or so, depending on night power license) audio pad on the right. The one on the right in your picture looks to be that board. Another option was a remote power cut back vacuum switch on a small board on the left. A motor operated plate rheostat was also an option for fine tuning output power. This rheostat was mounted lower on the right near the mod reactor.

I have seen several examples of circuits made by station engineers to do these jobs. The boards on the left look like home brew. Just my opinion, I don't recognize those boards, I would have to take a closer look.

Edit; I downloaded and blew up the picture you posted. The boards on the right look to be an audio pad with relay and RF power cutback remote switch.  The boards on the left, at the top of your circle, I recognize this. I have one that came with my transmitter as spare parts. I don't know what it is but your welcome to it. The aluminum box and relay below that are home brew. The standoff chassis is a mistory but I don't believe it is original.

[wx3k]

Ah, so these boards are remote control and power accessory control boards. This is good to know. I did not see these on the 20v2 I got pictures of which made me wonder what functions these boards perform.

In a word, no. If the transmitter was purchased from Collins with the Day/Night options installed you would have a relay operated 10 DB (or so, depending on night power license) audio pad on the right. The one on the right in your picture looks to be that board. Another option was a remote power cut back vacuum switch on a small board on the left. A motor operated plate rheostat was also an option for fine tuning output power. This rheostat was mounted lower on the right near the mod reactor.

I have seen several examples of circuits made by station engineers to do these jobs. The boards on the left look like home brew. Just my opinion, I don't recognize those boards, I would have to take a closer look.