[Boatanchors] BC 221 heresy

[Brian Clarke]

Hello Brian,

If you have a bunch of receivers, or transmitters for that matter, that you
like to have 'standardised', I have added a 6AK5 as an untuned RF output
amplifier inside the box - no need to drill extra holes - just re-route a
few wires - fed the output to the terminal on top, attached a very short
antenna and, lo and behold, you have a standard that does not need your
receivers to be connected to your heterodyne frequency meter.

The original headphones that went with these frequency meters did not have
any worthwhile output below about 300 Hz. So, some people believed that you
got 'spot on' by tuning exactly to the middle of the two places where the
300 Hz signal disappeared. Unfortunately, most people's ears are not that
accurate WRT frequency or level unless they have been trained, eg, as a
musician, or a piano tuner. And the actual shift in frequency between the
two 300 Hz points is not linear. So, my way around that is to set the
standard 1 kHz off your required frequency, split the feed to your
headphones and feed an accurate 1 kHz tone to one ear and then tune till the
heterodyne in the other ear matches the 1 kHz tone; the untrained human ear
is much more accurate there, and you can easily get to within 1 Hz or less. 

Apart from the Cardwell variable capacitor, the 1 MHz standard crystal is
worth retrieving. And in the LM series, the ceramic valve sockets. The audio
transformer in the LM can also be used if you are into single-ended, Class A
hi-fi.

You have three sets. I have a TS-175/U (that stays with me till I go in the
pine box), and on eBay presently, two BC-221s and two LM-13s.

73 de Brian, VK2GCE Sydney

On Thursday, 28 November 2019 9:05 AM, you said:

Apologies for repeat.. need to use my original mailbox for this List.

Sorry to ruffle feathers maybe... but I have three BC 221 or variants here.
Been here for a while now and I doubt I will ever be in a position to use
them as intended - if so I'd probably rely on modern methods that have
stable DDS tech.

My question is.. given the 'evil eyeball' my wife gives that stack in the
basement.. is there much inside those things to salvage out if I was to give
them a Viking Funeral? Any interesting stuff hardware wise (electronics I
doubt there is much), but if there is good variable gear stuff or whatnot I
guess I might be wise to hold on to anything 'good and interesting'.

This falls into early Estate Planning... I guess. Which is to say my friend,
when he retired, had a devil of a time either selling or giving away a 45+
year ham career in the basement. No takers on magazines, Harvey-Wells TBS 50
etc. He says start early and accept all possible offers!

tnx

Brian VE3VAW Toronto