[time-nuts] spectracom line taps

Bill Janssen billj at ieee.org
Mon Feb 18 22:08:09 EST 2008


John Ackermann N8UR wrote:
> jshank said the following on 02/18/2008 03:05 PM:
>   
>> Jamie,
>>
>> If you have the Spectracom 8140 you need to use the line taps.  With out 
>> using the line taps you sinewave will not be symmetrically along 0 voltage, 
>> that is the sine wave will all be positive voltage.
>>     
>
> I'm not certain about that; while I haven't used an 8140 amplifier, I
> have an 8164 WWVB disciplined oscillator that has an option installed to
> allow it to run a string of 8140T taps.  I was able to use those outputs
> directly by using a series cap to isolate the DC voltage; what's left is
> the 10 MHz sine wave.  As I noted in my other post, it does want to see
> a 50 ohm load (after the isolating cap) or the fault indicator may go
> on.  I suspect the 8140 amp is very similar; Spectracom did a lot of
> design reuse across their products.
>
> John
Be careful with that termination. If the  output has 12 volts DC you 
would need an isolating cap.
The Line Taps were intended for a production line where the taps could 
just be plugged in
and would get their power from the coax. Some were made that had a power 
jack and those
could be powered from a "wall transformer".

Bill K7NOM



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