Max I believe the inputs far more flexible then the limit suggested. Typically the low level is the issue. In the spec sheet I see it says .15V. If you had a 10 db anttenuator that would be a good start. The good news is it sounds like you have enough signal to drive both things pretty easily. Regards Paul.
On Mon, Jul 20, 2015 at 6:29 PM, M. George <[email protected]> wrote: > 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 > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
