Re: Question about 4S Tuner

John Lonigro

The tuner has two distinct parts.  If you are using it with a receiver, the only functional parts are the two switches (SW1 and SW2), the two variable capacitors (C1 and C2), and the inductor (L1).  Without a transmitter, the other part won't work.  For one thing, that part gets its power from the transmitter's RF - no RF, no power.

So all you have to check are the components I mentioned, as well as the connectors J2 (input from radio) and J1 or ( J3 and J4).

The first thing I'd do is toggle the IN/OUT switch to OUT and keep it there.  The "IN" position only works with a transmitter attached to J2.  That may have been your problem.  Tune in a station, then rotate C1, C2, and L1 to see if there's any change in signal strength.  Don't look at the LEDs.  They won't light.  If you get no change, you need to check your wiring on those components.

Good luck and 72,
John, AA0VE

On 1/9/21 7:55 AM, Timothy East wrote:
I built the tuner and cannot seem to get any response out of it.
I never experience the response shown on various videos.
There doesn’t seem to be any position on central knob with louder audio.
Examination of the build does not reveal any obvious issues. Does anyone have any suggestions?
It’s too bad really as the build turned out with a handsome unit I’d like to use with my BJ.


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