[ARC5] Fun with a 80 & 40 meter converter for the BC-453

Tue, 04 Nov 2003 16:10:13 +0000

You could build a dual frequency converter to bring the BC-454 and
BC-455 I.F. signals down to some frequency in the range of the
BC-453.  Then, all you'd have to do is tune the 80 and 40 meter
receivers.  That way, you'd be able to tune the entire range from
3.0 to 9.0 with outstanding selectivity.  Add a third crystal L.O.
and the 1.50 to 3.00 MHz receiver and you'd get outstanding
160 meter performance as well.

73  --- D C "Mac" Macdonald, K2GKK/5

----Original Message Follows----

From: "Tom Bridgers" <[email protected]>
To: <[email protected]>
Subject: [ARC5] Fun with a 80 & 40 meter converter for the BC-453
Date: Mon, 3 Nov 2003 23:25:11 -0500

Today I listened in on 75 and 40 meters using a BC-453 as a Q-5'er, which
was front ended by a 12BE6 converter.  I gotta tell you it brought back the
excitement of my novice days in 1954.  I was never able to get
my ARC-5's working back then, so this success today was a special treat.

There really isn't much to this 12BE6 converter. An RF coil, a 50 pf
variable cap, two RFC's, a few resistors and capacitors, and two crystals.
For 75 meters I used a 3640 crystal (which is what I had in the junk box),
and for 40 I used a 6800 kHz crystal (ditto).  The converter takes its power
from the BC-453.

The converter is sensitive ... and versatile.  To change bands, I just 
changed
crystals and adjusted the capacitor for best reception.  And the signals 
just
popped right out at me.

To be fair there were a few images, but what the heck.  For no more
circuitry than is represented here, this converter is amazing.

And the BC-453 was very stable.  I sat there tonight listening to the
Traders Net on 3898 kHz ( which was at 258 kHz on the BC-453 ) without
having to adjust for receiver drift.

All in all in this opens up a new dimension for me on using ARC-5's -- and
particularly the BC-453.  Why do I say that?  Well try listening to 80 or 40
with the BC-454 or BC-455.   I find that those radios have such poor
selectivity that after a while it's not fun.  Not so with the BC-453 and the
converter.  You don't get single signal selectivity, but pretty close to it.
And the selectivity is about a thousand times better than using the 454 or
455's barefoot.

Originally I wanted to build a converter that allowed me to listen to the
IF's of the BC-454 and BC-455.  But at this point,  would there be an
improvement in sensitivity or selectivity over using the converter?
However, I guess there would be an improvement in image rejection.
A negative to me is that tuning in signals via the IF frequency is
cumbersome.  I've been unable to go more than 20 kHz either side
of an IF without the signals dropping off significantly.  So then I have to
retune the BC-455 or BC-454...and then adjust the radio to which I'm
listening to the IF.   With the converter and a BC-453, dialing in a
frequency is easy and straight-forward.

I'd be interested  in what the experiences of other listmembers have
been (front ending BC-453's with a converter or using a converter and a
BC-453 to listen in to the IF's of the BC-454 or BC-455), and hope you'll
post them to the list.  Also if you know of references or articles about 
these
techniques, I hope you'll share that information with the list.  I'd sure 
like
to know more about this subject.

Thanks and 73's,
-tom  KE4RHH

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