[ARC5] BC-348 tuning rate and article

[howard holden]

When I was still a wee tyke my Dad bought a BC-348Q (which I still have). This RX served my Dad, brother, and me, providing code practice via W1AW. It also served for all of us to make many contacts in the day. To facilitate tuning, Dad affixed a stiff white paper ring to the back of the tuning knob using rubber cement. He put markings on it. The issue is not so much with bandspread or tuning rate, but with readout space. I forget how far the knob went from one end of 40M to the other, but he had it set so we knew pretty much where we were on the band. It was easy to get back to some point once you knew where things started. And the ring wasn’t permanent, no damage. The Novice band covered a few inches of dial OD as I recall.

Today when I use the RX, I simply set a marker from an LM-18 or other source at the bottom end of the band. Good enough for casual use.

73, Howie WB2AWQ

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From: Bob Groh<mailto:bob.groh at gmail.com>
Sent: Saturday, May 9, 2020 5:18 PM
To: Hubert Miller<mailto:Kargo_cult at msn.com>
Cc: ARC-5 Maillist<mailto:arc5 at mailman.qth.net>
Subject: Re: [ARC5] BC-348 tuning rate and article

Interesting thoughts.  Way back in the ancient days (well, really not that far back) when, by buying surplus gear,  we could get darned decent receivers for not a lot of money (which in those days many of us (who were quite young'ish (i.e. teens and thereabouts)) did not have a great abundance of) and we would do all kinds of funny stuff to those poor old relics to 'improve' them - mangle them to bandspread them, mangle the power supplies to fit our needs, etc, etc. Now we much older and, perhaps, a bit wiser folks, think " why the h*** did we do that silly thing..".  And yes, we are wiser. When we find them in more or less virgin state, let's leave them in as close to virgin state as we can.

73
Bob Groh, WA2CKY


On Sat, May 9, 2020 at 7:03 PM Hubert Miller <Kargo_cult at msn.com<mailto:Kargo_cult at msn.com>> wrote:
I was looking at the 73 Magazine, June 1963 Special Surplus Catalog Issue, page 18, "Bandspreading the BC-348."
Describes adding series capacity limiting caps to the 4 gang sections and then parallel caps also to place the bands
approximately at the same place. Says 80, 20 meter bands are now spread over 4x times as much dial travel and
40 meters now spread 3x as large. I never thought of the BC-348 as an SSB machine and actually, I thought for CW
use the bandspread, tuning rate was adequate and certainly better than many other era receivers we have used.
Article says these changes can be undone, if wished, in under 15 minutes. BUT - you are now dealing with a next
to useless dial readout, unless you make a new dial scale. Myself I would not execute this mod unless on an
already plentifully hacked example and anyway, I'm not sure it's even worth it. I wonder what you the readers
think about the BC-348 tuning rate and dial as - is. I tend to think it's already adequate and perfectly usable.

There was another article a few years later which did the same procedure and so enabled 15 meters hamband
coverage without modifying any coils.

I have a large German receiver, an AE4139 Siemens, which had general coverage and one dial only, and someone
post war retrimmed it to 80, 40, 20, 15 and made a whole new dial scale for it. I will leave that one as - is.
-Hue Miller
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