- January 18, 2019 at 7:12 am #108872Radio JoeParticipant
Total posts : 63
Has anyone built the Vectronics VEC 1290 K AM transmitter?
This Vectronics VEC 1290 kit a simple low cost LC no PLL transmitter and looks good. I am Just wondering how stable it is as far as holding frequency and also audio quality. I checked the schematic and there is not much out of the norm for small transmitters like this, and it has to be very low power as there is no amplification after the oscillator stage. The review I read says that the audio quality is good but that doesn’t tell me much.
If anyone can tell me just how flat the response is and how it compares to a commercial broadcast signal in respect to audio quality it would be great!. I know a person can’t ask for too much for $29 but you never know on these things! I like the way they have a built in antenna matching system though. So if anyone has built this transmitter and can give a firsthand account on comparison to on air sound of a standard broadcast I would like to see what you have to say.
Radio JoeJanuary 18, 2019 at 8:41 am #108874MarkModerator
Total posts : 535
Haven’t built but found a video with a sound check that may be helpful.January 18, 2019 at 9:34 am #108875Carl BlareParticipant
Total posts : 1540
The Vectronics AM Transmitter
Good video, Mark, I watched with interest.
Also I found you can download the PDF of the Manual from
The schematic is shown and the first feature that disqualifies this unit in my opinion is the simple VFO (Variable Frequency Oscillator) which must be hand-tuned to frequency and predictably will drift and need to be reset all the time.
What there is of it is well planned but seems to be designed somewhat under FCC part 15 specs, i.e., a 6-foot antenna rather than 10-feet.
It would be a place to start in the kindergarten of electronic education.January 18, 2019 at 9:35 am #108877Radio JoeParticipant
Total posts : 63
I thought the review was good, the person did a nice job of letting people know how things went. I thought the audio quality was good! the hum he talks about thats normal, I have it here on all my AM transmtters, has to do with house wiring and the rf mixing with line current in the house wiring. I might have t add this transmitter to my collection see what it does. Audio seemed full and had good bottom and top end.
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