Oooops!! (Re: Inexpensive SWL recievers)

[Chris Trask]

        Boy, am I ever embarrassed!  :{I  I got the GR-54 and GR-64
backwards.  You'd think I would remember better, after using a GR-64 for
many years.  Also, the solid-state receiver is a GR-78.  Just goes to
show what we all have to expect with age.  I wrote my response while at
work, relying on my memory.  Big mistake.

        The GR-78 has a VLF band, tuning 185-410kHz (per the dial).
Damned good receiver, and not the simplest to construct, as I recall,
due to the way that the front end, mixer, and VFO sections were built
in a shielded enclosure through which the band select switch shaft was
inserted after the boards were installed. The FET in the VFO circuit had
an incorrect resistor value in the drain, which at times prevented oscil-
lation.  This was remedied years later.

On Tue, 10 Nov 1998, Bill Coleman AA4LR wrote:

> On 11/10/98 4:49 PM, Chris Trask at ctrask at primenet.com wrote:
>
> >On Tue, 10 Nov 1998, Bill Coleman AA4LR wrote:
> >
> >> On 11/10/98 12:40 PM, Gary L. Sanders at gsanders at RICOCHET.NET wrote:
> >>
> >> >I had both the GR-64 and GR-54 when I was a teenager. The GR-64 is a
> >> >simple regenerative receiver, but with a nice look.
> >>
> >> The GR-64 is a four-tube superheterodyne receiver. Not a regenerative
> >> receiver. Has a big slide-rule type dial.
> >>
> >> The GR-81 is a three-tube regenerative receiver. Has a circular pointer
> >> dial covering about 300-330 degrees.
> >>
> >> If anyone has one, I'm looking for GR-81 parts to finish a restoration.
> >>
> >
> >     Uhhh...  The GR-54 was the four-tube superhet.  It was an
> >all-american 5 with a pair of diodes for the rectifier rather than the
> >usual tube.
> >
> >     The GR-64 was a much nicer receiver, with an RF stage thrown in.
>
> The GR-64 has NO RF stage. Antenna input when right from the input coil
> to the pentagrid converter (a combined oscillator/mixer).
>
> I believe someone else mentioned that the GR-54 had an RF stage. I also
> had the impression (and could be wrong) that the GR-54 may have also had
> a longwave band (ie 150-500 kHz).
>
>
>
> Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at radio.org
> Quote: "Not within a thousand years will man ever fly!"
>             -- Wilbur Wright, 1901
>


     ,----------------------.       Circuit Design for the
    /    What's all this     \            RF Impaired
   / extinct stuff, anyhow?  /
   \  _______,--------------'        Chris Trask / N7ZWY
  _ |/                               Principal Engineer
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  \  \    .'  `.                  Tempe, Arizona 85285-5240
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       c__; c__;  '-..'>.__      Email:  ctrask at primenet.com
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                    Graphics by Loek Frederiks

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