Ramsey Electronics HR30 Instruction Manual - page 16
HR30
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16
ALIGNMENT HINT FOR ALL DIRECT CONVERSION RECEIVERS:
You will clearly hear the oscillator of your kit - very close to its receiving
frequency, if you tune around for it on ANY shortwave radio covering the same
frequency range. Even if your shortwave set does not have a BFO (beat
frequency oscillator) for CW-SSB, you’ll still hear a powerful ‘hiss or quieting’
when your shortwave receiver is tuned near the frequency of the HR30. Your
shortwave receiver is actually picking up the oscillator signal within the HR30!
USING YOUR RECEIVER:
In your first tests, you might feel that tuning in CW and SSB stations by turning
the control shaft seems tricky. Don't despair! The addition of a simple knob to
the final version of your kit will result in more comfortable tuning right away.
Also, the larger the knob, the easier the tuning is. Even smoother control can
be accomplished by a vernier dial, which will also provide calibration marks.
Finally, if you intend to use this receiver only for monitoring or working a very
specific frequency range, you can add a resistor in series with the tuning
control to achieve the bandspread you want for your own application. For
details, please see the upcoming section, Notes to Experienced QRP
Builders.
We want you to enjoy this economical receiver, whether you use it for portable
listening or as a base for easy experimentation. Isn’t it amazing the
performance that can be achieved with just two IC chips?
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TUNING SSB SIGNALS
As you know, the protocol for the 160 - 80 - 40 Meter Bands is lower sideband
(LSB), with Upper Sideband (USB) used for 40 - 18 - 15 - 12 - 10 Meter SSB.
To check or ‘scan’ a given band for SSB signals, tune your HR30 up from the
low end for USB signals and down from the high end for LSB. Unfortunately
most signals on 30 meters will be CW or other types of digital
communications.
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CW OPERATION
A direct-conversion receiver lets you hear equal ‘sidebands’ on either side of
the zero-beat ‘null’ of the exact frequency of the signal to which you are
listening. Therefore, when adjusting the frequency of your companion Ramsey
QRP transmitter, be certain that you have in fact tuned to the other station’s
lower sideband. The two stations will actually be several KHz apart. Because
this receiver’s oscillator is not shared with a transmitter, as in transceivers,
there is no need for separate RIT (receiver incremental tuning).