|Customer Reviews for the VEC-1292K.|
|From: Theodore |
| Recently, I built that small FM radio transmitter. It only took a week or so to build.|
1. It didn't work at first. I found that a jumper wire @(JMP1) indicated on the pc board must be soldered between pin 12 of the IC and the junction of C4, C10 and C17. Otherwise, there can not be any audio applied to the modulator.
There aren't any instructions in the manual to indicate this.
2. Using a 33pF capacitor @(C18), the transmit frequency was only able to achieve a maximum of ~90 Mhz, not 94 as specified in the manual. Replacing it with a junk box 33 pf SM cap., provided the same results. Either the two caps were much greater in capacitance then marked or the Inductor (L3) was larger in Inductance then specified in the manual.
3. I installed a longer 24" telescoping antenna instead of the 19" one supplied with the kit. I noticed that the Field Strength had increased, somewhat.
Possibly, using a full size vertical dipole (~57") should provide a greater range!
4. To avoid leaving the transmitter turned on when not using, I installed a small LED and a 2.4K resistor in series from the 9V supply to ground.
Although it limits the current in the Led to ~3 ma, it is bright enough to see from across the room.
It is a great little transmitter, otherwise. I'm glad that I did buy it. I had been thinking about building a circuit from the Web but most of the them were just AM types, not FM.
|From: Theodore |
| Using a metallic tuning tool for Inductor L3 is not recommended because it will detune the oscillator frequency and it would make it rather hard to spot the correct frequency.|
Try using a wooden tool instead or just a "flat toothpick" for tune-up. It works GREAT!
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