[time-nuts] External 10Mhz referance levels

[Christopher Brown]

Thanks for the info.

It might be a little finicky, but the adjustment of the balance pot
varies a bit depending on the output level.


By following manual, 48db down at 20Mhz or better is easy.

Slightly backing off the forward core while watching the spec an takes
it to 55db down or better, but as you shift through the output range it
degrades to around 45db down.


Targeting to 0 to 10dbm output range be setting to +5dbm and tweaking
the pot results in 55db down or better from 0 - 10 dbm output.


On 3/31/12 2:19 AM, Ulrich Bangert wrote:
> Chris,
> 
> while there MAY be exceptions my rule of thumb is that none of the devices
> that I have seen until today was unhappy at a +7 dBm  reference level. My
> own distibution amp runs at +13 dBm (quite handy to drive a level 13 mixer
> directly from a well isolated source) and I drive all my devices with that
> which include
> 
> HP3330
> HP3325
> HP5370
> HP5342
> HP5359
> HP8660
> SR-620
> DS-345
> UA6200A
> Wavetek 278
> Racal-Dana 1996
> Anritsu MS2601B
> 
> without experiencing any problems. Don't look at the problem with the eyes
> of a ham: Unlike in most ham rf circuits a lot of these devices need to make
> a square shaped signal from the sine input and are happy if you support them
> with a not too small level. That is my experience but please don't take it
> as an invitation to test if EVERY device may be fed with 13 dBm without
> destruction. A look to the specs is never wrong.
> 
> 73s de Ulrich, DF6JB
> 
> P.S.
> Even if you consider that the reference input may have a 0805 50 Ohms chip
> resistor for termination its destruction level will be well above +20 dBm.  
> 
>> -----Ursprungliche Nachricht-----
>> Von: time-nuts-bounces at febo.com 
>> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Christopher Brown
>> Gesendet: Samstag, 31. Marz 2012 10:12
>> An: Discussion of precise time and frequency measurement
>> Betreff: [time-nuts] External 10Mhz referance levels
>>
>>
>>
>>
>> So, going through a surplus HP 5087A.  All torn down, cleaned 
>> and back together.  10Mhz input amp and 10 output amps.  
>> Manual talks about setting for 3V rms into 50ohms, all 10 
>> amps appear clean and a little extra time with a spec an 
>> gives -55db at 30mhz and < -65 or better for the rest.  
>> Dropping to 1V RMS and tweaking the balance pot gives -55 to 
>> -60 at 20 and 30, rest in the noise.
>>
>> All seems good, but what should I be feeding my gear.  All of 
>> the manuals are pretty sparse on details, mentioning minimum 
>> for a few, but no target or max.
>>
>>
>> Will be feeding
>>
>> 3596C
>> 5335A
>> 5370B
>> 8657B
>> 8395/E6380A
>>
>> to start.
>>
>> Maybe I am missing it, but the only mention of level I have 
>> seen so far is > -10dbm.  The suggested 3v rms in the 5087 
>> manual seems a bit high.
>>
>> Comments, suggestions, guidance?
>>
>>
>> BTW: Name is Chris, HAM since teens, playing with anything 
>> technical for longer than I can remember, packet data 
>> networking guy for last 18 years by day.  Getting around to 
>> putting together a decent workbench opposite the HAM station. 
>>  Never could stand owning/operating things I could not 
>> properly service, fixing the issue but first I need to figure 
>> out all the gear (and in some cases fix the gear that will be 
>> fixing the other gear.).
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to 
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.