Hi Running and shielding a 10 MHz standard signal is never easy. Ground loops here or there are highly likely to exist and create all sorts of issues. In some setups, -10 to -20 dbm is not an uncommon result ( = fix the termination on your Spectracom system …). Getting below -90 is actually doing pretty well.
Bob > On Jul 13, 2019, at 12:53 PM, Jerry O. Stern <[email protected]> wrote: > > I have been using a Tbolt and TAPR TADD-1 for a few years, mainly as an > external reference source for my workbench equipment. Just got a SDR radio > kit (Ubitx) and trying to calibrate the local oscillators found this > annoying substantial 10MHz signal heterodyning with the LO's (45MHz and > 12MHz). Taking a look on my SA with just a broad band telescopic antenna > in the SA input, I see a 10MHZ at about -55 dBm and no other signals > -120 > dBm. The Tbolt is about 4-5' away from the workbench BUT I disconnected > everything and it is only connected to the TADD-1 distribution amplifier > The TADD has no distribution coaxes attached, it is in the TAPR metal > cabinet which I always thought was well shielded and every port has been > terminated with 50 Ohm dummy load plugs. When I take the TADD-1 out of the > equation and just run the Tbolt into a 50 ohm termination plug, the 10MHz > signal on my SA drops down to > -90 dBM. I duplicated this with a > Lucent RFTGm-Xo/Rb pair and the TADD-1 with similar results. Has anyone > else seen this with their distribution amp? > > > > Jerry > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
