Real interesting info on SRS, Bob. I wondered how far you could get from the set up channel tunings when using an add-on VFO.
Among older sets, the GRC-13. It also has the single crystal, "crystal saver" type circuit.  50 kHz is not much but it is something.
At one time, i thought i'd collect Northern Radio ( Seattle), but that proved not practical. I have taken apart a number of old
Northern tubed radios and also a few of the later hybrid N550. The latter sets do have one, and if you're real lucky, two Collins
455 filters. I still have one N550 to go but sometimes i think, get rid of the vac tubes and the heavy heavy HV transformer and
just use it with the 5W PEP solid state final driver. It would be neat to be able to use the channel knob for tuning but...this
control seems to be wired right to circuit boards...a big mess. I also have a few of the later all transistor Northern radios.
Some have a "drift cancelling" circuit which i don't fully understand yet. But with the availability of DDS VFOs now, maybe
these can have a chance of living on. USB fits with the coverage of most of these high seas models which tuned up to 18 or
21 MHz.

I recall maybe 4, 5 years ago i gave a stack of Northern 711s to a ham radio friend. ( Who doesn't read this list. ) This was a
100 watt, 1.5 ( yes, you read that right ) to 9 MHz USB radio, pretty simple circuit, no kinks. This would have been a primo
candidate for any of the included bands, just change the channel control to a VFO. I also gave him some sets of "upgrade
kits" of some kind.  Now i regret like hell giving all those away. He is a great guy, but his Modus Operandi is buy low,
play with it for a while, then put on Ebay at marked up price. So i know where the 711s went, and the 2 of GRC-9 which i
sold him. He was talking to another fellow i know about buying that fellow's TRC-77, and i cautioned the other fellow, "You
can do what you want, but if you sell it to him, next thing you know, that radio will show up on Ebay, so be advised." 

I have thought of replacing the tube finals in some of these hybrid sets with solid state MOSFET PAs. Even 20 watt PEP would
be satisfactory, i think. Of course, you have to find room for the LP broadband output filters.
But i digress, as usual.
-Hue Miller

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