The AM Forum

Other than appearance, the meter,  and the crystal calibrator, is the Knight R-100 and R-100A the same receiver, with the same electronics, etc?

The crystal calibrator was an accessory for either model.
I think the only reason the R-100A exists is to match cosmetically, the Knight T-150 transmitter.
The might have been some circuitry changes (additional front panel knob on the R-100A) although they both used the same set of tubes. You would have to side-by-side compare both schematics and parts lists.

R-100 has 11 knobs on front panel:

(https://www.universal-radio.com/used/UC40lrg.jpg)


R-100A has 12 knobs on front panel:

(https://www.radiolaguy.com/images/Com-Gear/Knight_R-100A-b.jpg)

Thanks Pete, that about what I have determined also. The layout of the original 11 knobs look to be in the same general position, and pictures of both receivers looks exactly the same.  I just bought a 100A to match my T-150, and want to bring them back to working as well as possible.  I may come looking for someone who aligns receivers, as I do not have the ability or the equipment to do that.
Thanks for your reply.

The ebaman site (NOT ebay) has the R-100A manual for download, it is free but you do have to register.  The same site has most of the Heathkit ham radio gear manuals:  https://ebaman.com/remository

The T-150 does have pretty high spurious output, if you use an external antenna tuner which also acts as a lowpass filter (many of them do) it will clean it up some but you should also take a look at W8JI's excellent analysis of this transmitter and consider making the changes he suggests:  https://www.w8ji.com/allied_knight_t150.htm

Rodger WQ9E

Rodger, I appreciate that link.  I have bought 243 crystals for 3880, 3885 and 7290 and 95, and plan to steer clear of the VFO.
Although when I get time, I may do those updates. Thanks a lot.
 Bob