[Milsurplus] Hacked-Up BC-342 Question

[Ray Fantini]

After the internal power supply, configuring the filament string to run from 6.3 volts, changing the audio output transformer and adding a S meter a lot of other weird stuff was published. One common item was to add separate AF and RF gain controls instead of the common gain control. Another was to add a triode amplifier between the detector and the audio output stage along with changing the output tube to a 6V6 or 6L6, the original 6K6 had plenty of output especially when you change the output transformer to a regular transformer to match a speaker but imagine some people wanted loud audio? There were also modifications to the screen resistors of the RF stage and modifications to the crystal filter to add a phasing control so all that can account for more knobs.
On a receiver that has been hacked to begin with going back to the original design with the included AC power supply, six volt filament string, low impedance audio output and S meter makes for a good band cruiser for AM operations, yea I know it's not historically accurate but it works for me.
RF

From: Joe Connor [mailto:joeconnor53 at yahoo.com]
Sent: Friday, June 22, 2012 9:37 AM
To: Ray Fantini; Milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] Hacked-Up BC-342 Question

Thanks, Ray.

I'm still trying to get a grasp on what mods were done. The 1st RF tube is one, as is the addition of an S-meter. I'm not sure why the fast-tuning mechanism was removed. With that gone, this tunes like a BC-348. From the work I've done so far, I see it still has the original Micamolds in the IF, 1st Det. and RF Osc. cans so maybe the electronics were not modified all that much.

Speaking of hacked-up BC-348s, I have one in my basement that you would not believe. I bought it out of sheer curiosity. The prior owner must have added 10 pots and toggle switches. I had never seen such a heavily modified receiver. It reminded me of someone converting a toaster into a blender.

                                                     Joe Connor

From: Ray Fantini <RAFANTINI at salisbury.edu<mailto:RAFANTINI at salisbury.edu>>
To: Joe Connor <joeconnor53 at yahoo.com<mailto:joeconnor53 at yahoo.com>>; "Milsurplus at mailman.qth.net<mailto:Milsurplus at mailman.qth.net>" <Milsurplus at mailman.qth.net<mailto:Milsurplus at mailman.qth.net>>
Sent: Friday, June 22, 2012 8:25 AM
Subject: RE: [Milsurplus] Hacked-Up BC-342 Question

6SK7 was used in the BC-348Q and in many of the conversion articles of the time it was recommended that the two 6SK7 tubes in the RF amplifiers can be switched out for 6AC7 that was supposed to improve the front end of the radio. 6AC7 and 6SK7 are wired the same so no changes are necessary.
If it's a really hacked 342 maybe you should consider building a "Ham" version of the receiver, incorporate all the CQ modifications and keep it as a example of what Hams were using in the fifties and sixties. That's what I did with a old BC-348 that I got that was hacked and using that set for copying AM on 40, 80 and 160 is always good. That radio gets used for listening on 3.885 and 7.29 a lot.
When I am on the air operating on 1.885 or 7.290 AM will use better radios but for just listening to what's going on when doing something else the BC-348 works great.
RF

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net<mailto:milsurplus-bounces at mailman.qth.net> [mailto:milsurplus-bounces at mailman.qth.net<mailto:milsurplus-bounces at mailman.qth.net>] On Behalf Of Joe Connor
Sent: Thursday, June 21, 2012 6:31 PM
To: Military Surplus Mail List
Subject: [Milsurplus] Hacked-Up BC-342 Question

I just started working on a very hacked-up BC-342 that was stashed away in my basement. The cosmetics are a nightmare.

On first inspection, I see that the 1st RF tube, which is supposed to be an 6K7 (VT-86), is actually a 6SH7. The grid cap is missing and the former grid-cap lead is apparently wired to the underside of the tube socket.

Is anyone familiar with this mod? Does a 6SH7 make sense in this application? If not, what non grid-cap tube makes sense? If the prior owner simply wanted to use a non grid-cap tube, wouldn't the 6SK7 make more sense?

As always, thanks for your advice.



                                       Joe Connor ______________________________________________________________
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