how to use the hammarlund hq 145a (tunning)

[Fernan Bolando]

hi all

i was listening to a few stations using my hammarlund hq-145a. i noticed that
the band spread dial seems close in terms calibration. The main dial after
i set the bandspread to 100 vertical line, stations seems 450 to 550kcs off.
I tried to listen to a reference oscillator i can hear it in two places using
the main dial. i hear it on both -250kc and +500kc approximately.

does this make sense to anybody?

regards
ferna ve4feb

[Ralph Mowery]

Post by Fernan Bolando
i was listening to a few stations using my hammarlund hq-145a. i noticed that
the band spread dial seems close in terms calibration. The main dial after
i set the bandspread to 100 vertical line, stations seems 450 to 550kcs off.
I tried to listen to a reference oscillator i can hear it in two places using
the main dial. i hear it on both -250kc and +500kc approximately.
does this make sense to anybody?
regards
ferna ve4feb

If a receiver has an IF of 455 kc then it is possiable to receive a
signal at its origional frequency on the dial and an image signal 455
kc away from it.

The local oscilator in the receiver mixes with an incomming signal and
generates a signal plus and minus the IF .

Do a Google search for image frequency for detailed information.

[Fernan Bolando]

Post by Ralph Mowery

Post by Fernan Bolando
i was listening to a few stations using my hammarlund hq-145a. i noticed that
the band spread dial seems close in terms calibration. The main dial after
i set the bandspread to 100 vertical line, stations seems 450 to 550kcs off.
I tried to listen to a reference oscillator i can hear it in two places using
the main dial. i hear it on both -250kc and +500kc approximately.
does this make sense to anybody?
regards
ferna ve4feb

If a receiver has an IF of 455 kc then it is possiable to receive a
signal at its origional frequency on the dial and an image signal 455
kc away from it.
The local oscilator in the receiver mixes with an incomming signal and
generates a signal plus and minus the IF .
Do a Google search for image frequency for detailed information.

that is what i thought too and it makes sense when the tunning range is set to
4-10 mcs. The man dial is off by approx -120 to -200kcs and the image is
455+455kcs away from that.

but at tunning range 10-30 the double conversion is suppose to remove the image
frequency right? any chance i might be overloading the front causing weird
harmonics in the mixer?

fernan

[Scott Dorsey]

Post by Fernan Bolando
i was listening to a few stations using my hammarlund hq-145a. i noticed that
the band spread dial seems close in terms calibration. The main dial after
i set the bandspread to 100 vertical line, stations seems 450 to 550kcs off.
I tried to listen to a reference oscillator i can hear it in two places using
the main dial. i hear it on both -250kc and +500kc approximately.
does this make sense to anybody?

If you turn the reference oscillator level down, is there some point at which
one of those two signals abruptly disappears?
--scott