[MarkG]

If you are familiar with the Collins VHF-251, please give me a shout.  I am looking for operating instructions and any hints about swapping out a VHF-250 for it.

-- MarkG

[Avionics]

VHF-250, VHF-251, VHF-250S, VHF-251S, VHF-250E, and the VHF-251E all share the same rack. No wiring changes. Is this what you wanted to know?

[slacktide]

If you are familiar with the Collins VHF-251, please give me a shout.  I am looking for operating instructions and any hints about swapping out a VHF-250 for it.

-- MarkG

Pinout diagram...

http://www.flycorona.com/manuals/Colins_VHF250-251series_Pinout.pdf

[MarkG]

Well, I already know it (VHF-251) is plug-compatible, I wanted to know how many frequency memories, plus any experience anecdotes, and troubles to watch out for...
Have gotten some good use from it already since first post...

-- MarkG

[Avionics]

it can only store one frequency at a time.

One of the biggest frequent problems with them is the "Store/Recall" feature. Its spring loaded towards store. Be gentle with it. The gearing is made of plastic thats very old, and breaks easily. NO parts available, if it breaks.

The other problem is the transmitter can sometimes start to "FM-ing" during transmitt. I have long ago forgotten what it takes to fix this problem. But these radio's are available so cheap, its not worth fixing.

Hope this helps.