[Collins] Using an AStatic D-104 with Collins rigs

[Jim Isbell, W5JAI]

I use an HC 5 but I also use a transformer (supplied by Heil) and it
works fine on my S Line.

On 7/15/05, Barockteer at aol.com <Barockteer at aol.com> wrote:
> It's a simple matter of impedance matching...
> 
> The D-104 crystal element nominal output impedance is very high, above 1
> Megohm. This should have driven the high input impedance of various Collins rigs
> fine, albeit with some rolloff.
> 
> The HC-5 mic element has an impedance of 2K ohms nominal. This means it will
> not produce enough signal into the high input impedance of the Collins rigs.
> 
> I would suggest you replace the element in the D-104 with a direct
> replacement. You're looking for an MC-320 element. Then, if you want to improve the
> response, increase the input resistor of the rig to 1 Meg or better.
> 
> The best thing I've found is to get a T-UG8 amplified stand. Add a series
> resistor on the input of 1-2 Meg, and carefully adjust the amplifier gain so as
> not to overdrive the rig. I use this and it sounds great, especially with the
> KWS-1 or 32V which have wider bandwidth.You may also be able to use the
> amplifer with the HC-5 element. Or, try to find an audio impedance step up
> transformer.
> 
> 73,
> 
> -Tony
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> 


-- 
Jim Isbell
"If you are not living on the edge, well then, 
you are just taking up too much space."
W5JAI
1967 UltraVan #257
1936 SS-100 (replica)
1970 E-Type
1982 XJ6
1985 XJS
1988 XJ40