[time-nuts] TBolt 10 MHz output ~1.7v rms / HP 8656B FG

[M. George]

I picked up an HP 8656B from the usual place and have been cleaning it
up... got around to testing the output which looks good on a cheap
frequency counter etc...

I'm wanting to use the 10 MHz output from my TBolt for the reference input
on the HP 8656B and my Elecraft K3.  So I started digging around in the
manuals I can find on the internet, including KO4BB's cool manual stash.

I'm not finding the specs on the input for the reference on the 8656B.  I
found an older reference for the 8646A that said to keep the input rms
voltage between .2 and .4 volts, which scared me, because I had already
hooked up the Tbolt direct.

If this is correct, then .2 vrms - .4 vrms is around +2 dbm.

The direct output on the TBolt to my scope is showing ~1.7 vrms which is
close to +17 dbm.  Yikes, I had that hooked up to the 8656B for a while...
I hope I didn't screw anything up.

I have a K3 with the EXREF board hooked up direct to the TBolt and it's
happy as a clam with the 1.7 vrms input.  Which is a tad bit high for the
Elecraft docs which shows a nominal level of +4 dBm to +16 dBm.  I'm
assuming the 1.7 vrms is falling in to the 'nominal' range.

I'm not finding dire warnings about hooking the TBolt 10 MHz output direct
to a K3EXREF or an HP FG...

I don't have a frequency counter that takes an external reference (yet), so
it's hard to know if the HP 8656B is using the external reference.  Again,
I can't find much in the manuals to validate the external input, other than
using a FC with the same reference input.

Any input or tutoring would be helpful.  Are others just adding resistance
in line with the TBolt output to drop voltage?  I tried a 50 ohm resistor
and it dropped from 1.7 to just under 1v rms on the scope.

Thanks

Max NG7M

-- 
M. George