[50mhz] adding AM to an old FM receiver - questions

[Patrick J. Jankowiak]

Hi All,

I mostly lurk here, having little time due to work, but soon my antenna 
will be up and I want to participate in the 6 meter fun.
For 6M, besides some very low powered gear, I have only a Link 250UFS 
base station, which is FM. It takes crystals, but I can substitute 
existing external VFOs for the TX and RX crystals. The Link is 250W and 
uses a 250TH final. It has separate TX and RX.

My question is whether anyone has successfully added or modified an FM 
receiver of this general kind so that it could receive an AM signal.

The RX has a string of two  I.F. stages, acting as limiters. Maybe some 
ACG? I am not sure what to do and I do not want to hack up the set 
irreversibly.  (for  SSB  an external detector could be added once it is 
capable of AM)

complete info here - click on the logo: 
http://www.bunkerofdoom.com/kd5oei/link/linkindex.html
The unit in question is the larger one - the 250UFS. However, it has the 
newer receiver, the "Ed. 7" receiver shown in the material for the 
smaller 50-watt unit.

For a direct look at the receiver in question please look here:

There is a GIF of the schematic here: 
http://www.bunkerofdoom.com/kd5oei/link/linkmenu/link_50ufs/l0000000114.gif 
but it is not very good.

The 23MB PDF file has a much better diagram on page 15 of the PDF:
http://www.bunkerofdoom.com/kd5oei/link/linkmenu/link_50ufs/Link_50UFS.pdf


 Thanks for taking the time to look at the diagram if possible.

Patrick KD5OEI