[BC] Weston VU Meters

[doug@schleutker.net]

Thanks Bob,

This is the way I remember it.
What I could not remember (and why I was vague) was whether the 3600 or 3900 resistance was internal.

Thanks for clearing that up.

Douglas E. Schleutker
Vista, CA
doug at schleutker.net 



*********** REPLY SEPARATOR  ***********

On 11/10/2005 at 9:06 PM Bob Foxworth wrote:

>I can add a bit to this. My recollection of the internal impedance of
>a standard VU meter was it being 3600 ohms. When this was
>put in series with a 3900 ohm external resistor, the bridging
>impedance across the terminated 600 ohm line was 7500 ohms.
>Then the 3600 + (600/2) matched 3900 ohms. This external
>resistor provided the proper meter pointer damping.
>
>I am hazy on this but I think the meter read 0 VU at a +4 dBm
>level when the fixed 3900 was used. This could be replaced
>with a Daven step attenuator which may have been 7500 to 3600
>ohms. The line went to center and in and the meter went to
>center and out.  When I got into radio in the 60's I really splurged
>and bought a Simpson 4 inch VU meter with two 47 bulbs for
>illumination, and one of the Daven step attenuators. I think it
>ranged from +2 to maybe +20-ish? These things cost as I
>recall about $60 each which is what I made in a couple of
>days but I was 22 and single and had little else to worry about
>in life, and thought it was really cool to have pro equipment
>like this. I had them until the mid-80's, all mounted on a 5-1/4
>panel, along with a 600/600 non-detent Tee pot   What fun...
>
>Bought all that stuff at Harvey Radio on west 45th street,
>cash, over the counter.
>
>When I first started in NYC radio they gave us a thick printed
>set of documents with all this stuff printed on it. Wish I had
>kept it.
>
>- Bob Foxworth
>
>
>
>.
>
>
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