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If there is other strong signals in the filter’s band pass and the instrument has trouble locking on to the
received carrier, select a narrower filter and repeat the above procedure.
Unfortunately the HP3586 can’t be easily used as a receiver when controlling a transmitter, see section
16.11 of Chapter 16 for a possible method. It only has a SSB product detector and only displays the center
RF frequency that its filter is tuned to, so after locking onto a carrier, you will have to turn the volume
control knob full CCW to kill the carrier’s tone in the speaker. Then use your outboard receiver to copy
the other station.
5.4 Checking Your Instrument’s Frequency Calibration – HP recommends that the instrument be
calibrated each year. Unfortunately most of us don’t have access to a calibration lab and can’t afford to
pay a lab to do this for us. But we can check its frequency calibration using one of the frequency standard
WWV stations. Select a wide filter to make it easy to tune in one of the WWV stations, press [3100Hz] or
the button for your widest filter. With the same setup as the previous section tune your instrument to one
of the following frequencies, 2.500MHz, 5.000MHz, or 10.000MHz. Be sure to have an antenna
connected to your instrument’s unplaced input.
Turn up the audio volume on the audio sub panel to find a frequency where WWV is well above the noise.
You should hear a strong tone from its carrier in the filter’s pass band. You can also confirm you are tuned
to WWV by tuning the tone for zero beat using the frequency tuning knob and listen for the announcer to
identify the station as WWV in its AM side band. Be careful since WWV will send tones at times that you
could lock onto by mistake, it’s better to tune when their tone is off. Now retune the carrier to the filters
center and switch to your 400Hz filter being sure the WWV carrier is within the filters pass band.
Now press [COUNTER] on the frequency/entry sub panel and read what your HP3586 says the WWV
carrier frequency is. The difference from exactly one of the above frequencies you first tuned to is the
frequency error in your HP3586 since WWV stations have their frequency held to within a small fraction
of a cycle. See section 16.8 of Chapter 16 for a suggested way of keeping your HP3586’s frequency
accurately calibrated. Also see section 2.4 of Chapter 2 to see if you have the 004 frequency standard
option and if it’s activated.