Re: Collins 310

[k4kyv]

I noticed the listing on ePay. It nominally is one of those "all-band, 80 thru 10m" rigs, typical of the 1950s.  But it will work nicely on 160. That's the fundamental frequency of the PTO. I helped Roger, N4IBF(SK) convert his, which was an early unit with plug-in coils.  We just made up another set of coils, and he mentally divided the 80m dial reading by two. Roger used his as a VFO for his BC-610.

I think they eventually came out with a later model that is band switching, which would make conversion more involved, but it might still be possible since the PTO fundamentally operates on 160m. The first photo on the QSL.net site looks like a bandswitching version, even though they describe it as using plug-in coils, as shown in the second photo of the interior.

310B-3
Collins 310B-3 RF Exciter. This unit uses plug-in coils for band switching. It employs a type 70E-8 PTO and 2E26 RF amplifier tube and delivers 10 watts RF output. Production year: 1947

http://www.qsl.net/la5ki/org/co/co.htm

http://www.qsl.net/la5ki/org/co/310b3.htm

The one shown on the current ePay listing apparently doesn't  have the 2E26 output.  Collins made a low-power version without the final; I don't remember which one Roger's was. But the one shown must use plug-in coils, since there is no bandswitch on the front panel. That makes it a breeze to add 160m.

[Todd, KA1KAQ]

The 310 on ebay right now is the C model, Don - basically a VFO for plugging in to the crystal socket of a big HB rig. There were 3 versions: 310A, which was sold for use with the 30K transmitter, 310B which came in multiple versions, and the 310C, which came in two versions: with or without internal supply.

The 310B was more like a QRP transmitter, utilizing the 2E26. It also had provisions for adding your own antenna network by removing a front blanking plate which had a silk screened reverse side, drilling it to fit, and reinstalling. The 310B-3 included the network from the factory.

They are neat little rigs which offer that famous Collins PTO stability, accuracy, and reset-ability. Ebay prices tend to be considerably more than real world utility value. Was a time they were snapped up quickly for anything approaching the current asking price of the one listed. This example has been re-listed numerous times without selling.