Hello

I returned from Iraq last summer and decided once things settled down, I wanted to finally take the time to learn a little about electronics. I built some small projects, and spent countless hours reading books and internet offerings. I’ve flown radio control giant scale aircraft for about 30 years, and have learned to solder pretty good over the years.

That being said, I was given an old Tektronics 753 scope, and a really old Heathkit LC-1 RF generator.
The scope and I have come to terms, and I can get around it OK.
The RF generator is another story though.

The latest project is an AM/FM radio kit from Elenco. I picked it because at each stage of building, it allows you to make some tests and understand the theory behind what was just done.

So here is my question.
The Elenco manual says,
“Set the output of the RF generator to 455Khz, no modulation, and minimum voltage input. Turn the power to the radio on, and slowly increase the amplitude of the generator until the voltage at test point 5 just starts to drop. This point is called the AGC threshold with no IF gain.

Setting the generator to 455Khz is not a problem

No Modulation – I can use some help on this one?

Minimum voltage output – How are voltages set and read on the generator?

Slowly increase the amplitude – Need lots of help here. How would I increase the amplitude of the RF generator?

Any links to good tutorials would be great too!

Thanks for any help
Bob

 

Hi Bob,

It is assuming you have an RF generator that has amplitute modulation built in, with controls to vary the frequency and amplitude of the modulation (to simulate the audio signal you would be receiving) to align your AM radio. Likewise, you would need one with frequency modulation built in to align your FM section.

 

Here is a link to what I have.

Not sure how to answer your questions yet_bob


http://cgi.ebay.com/Heathkit-LG-1-Signal-Generator-AM-Shortwave-Tube-Radio_W0QQitemZ190068107969QQihZ009QQcategoryZ97198QQcmdZViewItem