[Milsurplus] QST BC-455 Hack

[wf2u at ws19ops.com]

I also have to confess that I committed surplus equipment hackery in  
my youth when I didn't know any better.
I made a double conversion receiver out of a BC-348 and a BC-453. I  
stripped the IF stages of the BC-348 except for the BFO, put in the 85  
Kc IF transnsformers from the BC-453 and the BFO coil. Detuned the  
original 915 KHz BFO oscillator by 85 KHz, mixed that with the 915 KHz  
IF, fed it into the 85 KHz IF string/BFO, built a product detector and  
audio-derived AGC with selectable time constants. Boy, was it a hot,  
stable and great working receiver! This was in the mid 60's.
There is no way I'd do anything like this today. I use my surplus  
stuff as they were issued.
Talking about some modifications not working worth a darn - Recently I  
restored and put on the air an early WW2 era Navy aircraft ATD  
transmitter. It had some modifications in the final stage, an 814  
tube. As I got it, it put out about 2.5W. I restored it to original,  
and got back the 40W output as it's supposed to work. This is another  
example of people modifying stuff without the knowledge and then  
ending discarding or stripping the gear, thinking the equipment is  
faulty.
Output matching is tricky with this transmitter as it originally  
worked into short aircraft antennas like the Command Set, but the ATD  
has a variometer output coupling and the matching range is more  
limited. I used a 100 pf series capacitor (on 80 M)  and it loaded OK.  
I'm now using a variable PI- section antenna tuner modified from an  
old MFJ unit. Works great.

73, Meir WF2U
Landrum, SC

Quoting Revcom <revcom at wbsnet.org>:

> Hue,
>
> You are right, I stand corrected!  I had read both articles on the
> Command sets, the transmitter article by W8KGI and then the receiver
> one by AD5X. W8KGI mentions the previous conversions (aka "butchered")
> and I read it into the Rx article I guess.
>
> I agree, was very prevelent in the '50s and '60s, I am guilty of
> tearing up many units back then myself.  Most of the "modifications"
> never worked worth a darn.  However used a BC-453 as 2nd IF and then a
> BC-458, CE converted VFO.
>
> Pardon me....
>
> Rod
> K0EQH
>
> ----- Original Message ----- From: "Hue Miller" <kargo_cult at msn.com>
> To: <milsurplus at mailman.qth.net>
> Sent: Monday, December 15, 2008 3:21 AM
> Subject: [Milsurplus] QST BC-455 Hack
>
>
>>
>>> Of course Hue, he mentions most equipment
>>> that you find will already be
>>> "butchered" to some extent.
>>> Rod
>>> K0EQH
>>
>> I looked thru the article a couple more times
>> and failed to find the the mention you quoted.
>> At the start of the article it's called a "modification
>> and update process", while at the conclusion
>> he advises this is one of the easiest "boatanchor
>> restorations" you could attempt. ( Not "restoration"
>> in the usual sense. )
>> At the ARRL website i do get to "vote" on whether
>> i enjoyed this article, which seemed more
>> appropriate to CQ magazine around 1955.
>> -Hue Miller K7HUE
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