[HBR] 85 KHz IFs

[Peter Bertini]

Those IF cans had a very, very narrow tuning range, the trimmer caps were
too small value to have much authority over the IF frequency. You may want
to add some external fixed padders or trimmers to get them exactly on
frequency.  The neat feature of those cans is that you can remove that
little black cover, and adjust the coupling between the coils to set the
bandwidth.

Some guys have salvaged the mica sockets and male connectors from the old
BC-xxx chassis in order to use the existing mounting system.  You can
directly solder to the female terminals on the base of the transformers,
however.

Pete

On Thu, Nov 20, 2014 at 8:03 AM, Shoppa, Tim <tshoppa at wmata.com> wrote:

> That tube lineup you mention sure sounds like a BC-453.
>
> Tim N3QE
>
> Sent from my Windows Phone
> ________________________________
> From: William Wood<mailto:ke9xq at charter.net>
> Sent: 11/19/2014 10:11 PM
> To: hbr at mailman.qth.net<mailto:hbr at mailman.qth.net>
> Subject: [HBR] 85 KHz IFs
>
> Greetings Folks
>    Traveled a short distance today to pick up my new
> 85 KHz Ifs, and a 65 KHz IF if that thing is labeled right.
> 2 x 85 and 1 x 65  I wonder what the range will be on each?
> 36 miles away, 72 round trip, but the roads were in good
> winter driving conditions.  And well worth the little side trip : )
> Can't remember what the gent said that they came out of, I
> think it was a BC 453???   Do not remember the facts, just
> know I'm getting closer to the parts listed that is needed.
>
>    Have a few shorter cans too, do not know what they are
> as of yet, but they came out of the same receiver.
>
>    Did you guys modify the base, these are female holes
> that sit down over pins.  Can't remember how they were
> put into action, I guess I need to find that printout : )
>
>    Now I have to find that schematic again and see
> what I needed.  Had a thought today, I have a bunch of
> Octals, and was thinking of going the octal route, but I
> think I shot that down right away for two reasons.  One is my
> lack of technical skills to do all the sub work, and the second is
> probably the newer miniature tubes would have better all
> around performance.
>
>    Now that I argued myself out of that idea folks, any ideas
> pro or con on the subject???   I like the "older" idea, but
> newer idea is better performance...
>
>    Kees or someone, I know I printed out the book materials
> and have it around here 'somewhere' I still would like to get
> a copy of the CD again, Happy to pay the ten spot.  I think
> I wrote to the other gent that archived the history and offered
> to buy his disk too, but still have not heard from him.
>
>    Think I will go to the archiving sites tonight, and se if I can
> at least download the schematic for the HBR 13C so I can
> ruminate a bit more on the subject : )
>
> 73 Everyone
> Bill  KE9XQ
>
> PS  Keep digging, those parts are out there, some of which
> might take a couple of years to find, but they are there,
> I have faith in our hunting abilities : )
>
> PSS the tubes that came in the little box were:
> 12A6 GT, 12SK7 GT, 12SK7 GT, VT131 (ANOTHER 12SK7)
> 12SR7, AND A 12K8.  If that gives anyone a hint as to where
> the parts came from.  Cheers
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