0
\$\begingroup\$

I'm in the process of applying for an FCC experimental certificate so I can be legal when I purchase a satellite generator.

I found a used (calibrated) generator on eBay and want to know if I need a dummy load on the RF outputs that aren't being used. The is one on the front limited to -110 dBm and the one on the back is labeled CAL/MON and is always on and transmitted at -48 dBm.

I understand those signal levels are VERY LOW. Do I still need a dummy load on the unused port?

\$\endgroup\$
  • \$\begingroup\$ do you mean dBm ? Please add datasheet, etc. describing the generator, I would say in generic, to terminate every unused output. \$\endgroup\$ – Tom Kuschel Feb 10 '17 at 18:02
  • 2
    \$\begingroup\$ What does the manual say? \$\endgroup\$ – Nick Alexeev Feb 10 '17 at 18:16
  • 1
    \$\begingroup\$ With that low power, pretty much all 50 ohm terminators should be good enough as a dummy load. \$\endgroup\$ – AndrejaKo Feb 10 '17 at 18:21
  • \$\begingroup\$ Yeah, that makes sense. Datasheet shows nothing about terminating unused outputs. \$\endgroup\$ – Samee87 Feb 10 '17 at 20:56
1
\$\begingroup\$

After consulting with the manufacturer, a dummy load is not typically used on signals lower than -70dBm as a rule of thumb. To paraphrase the response I received, the VSWR due to an open load at such small signal levels does not negatively affect transmission line characteristics internal to the generator.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.