[Collins] R-388

[Dr.Gerald N. Johnson]

Dr. Gerald N. Johnson, Electrical Engineer
----- Original Message -----
From: telegrapher at att.net [mailto:telegrapher at att.net]
Sent: 8/10/2005 10:52:18 AM
To: geraldj at ispwest.com;Collins at mailman.qth.net
Subject: Re: [Collins] R-388

> Sure a lot of differences in the manuals.  I have a 51J-4 that a local 
> ham loaned me for evaluation and i think he said it was an upgraded 
> R-388 because it has the mechanical filters in it.  Said it was kind of 
> rare because of that feature.  Now i wonder if all 51J-4 units are just 
> upgrades from the R-388/51J-3 series and whether this was a post 
> manufacture mod or something that Collins started doing at the factory 
> sometime during the 51J-4 production run?
> 
> Larry
> W0OGH
> 
The mechanical filter module is so modular that it could have been installed in a 51J3 to make a 51J4. Not much front panel change, just the lever sticking out from under another knob. I think it was available as a field mod kit. Much like the field mod kit for S-line to add the second crystal board, it probably was sold as a kit, intalled at the end of the production line, installed in the service department and built into radios as they were assembled on the line.

There being much handwork in the 51J receiver mods to particular radios on or near the production line were not difficult to accomplish.
 
73, Jerry, K0CQ, Technical advisor to the CRA
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