[MRCA] Whatzit? R-57/ARN-5 part.

[Mike Morrow]

Mike,

That's the crystal box that mounts on the rear of the R-57/ARN-5 3-channel UHF Glide Slope receiver.  The crystal box for the 6-channel R-89/ARN-5 receiver is identical, except that the three unused crystal socket holes are populated with three more sockets and crystals, which make use of all six installed crystal select relays instead of only three of them for the R-57.

It was forward thinking when the R-57 was made to have the ability to do an easy field mod to change from 3-channel R-57 to 6-channel R-89, but I don't know it that was ever done in real life, rather than just making more R-89 units.

Mike / KK5F

-----Original Message-----
>From: Michael Hanz <aaf-radio-1 at aafradio.org>
>Sent: Jan 26, 2018 8:13 AM
>To: MRCA at mailman.qth.net
>Subject: [MRCA] Whatzit?
>
>A friend in Colorado picked up the oddity in the attached photo and was 
>wondering what it was.  No nomenclature anywhere, just three CR-1A 
>crystals and six relays in a box.  Under the relays the box is engraved:
>
>Channel GX
>6497.917 KC
>
>Channel GY
>6522.917 KC
>
>Channel GZ
>6547.917 KC
>
>Anyone have any interest in it?