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My ATM3000 is finally compleate, but I’m having a problem. No matter how I adjust the knobs my signal sounds overmodulated. I fear I may have overheated one of the chips. Anyone know if I can get indifivual parts from sstran?
My ATM3000 is finally compleate, but I’m having a problem. No matter how I adjust the knobs my signal sounds overmodulated. I fear I may have overheated one of the chips. Anyone know if I can get indifivual parts from sstran?
Total posts : 45366Sorry you are having problems… first try to insure that you do not input more than 1 volt peak to peak on the audio… second if you are using the wire antenna, insure that the rf inductors are shorted and insure a good ground.
If you have all the above in place, try to get at least 8-10 volts at the meter when tuning… you will not get 13 volts at the meter unless you have a good radial system.
If you still have problems, it’s best to send the unit to Phil at SStran, he is most helpful and will repair and calibrate the transmitter for you… trust me on this, he’s done very well for me and he’s an excellent guy to work with!
Best luck…
Radiopilot
Total posts : 453668-10 yea right, at best I’ve only gotten 3v. I must have done something wrong. Time to Call Phil.
I got alot of good ideas. Problem is, most of em suck.
George Carlin (WINO)
Total posts : 45366You can email SSTRAN (Phil is quick to answer and very helpful), but meanwhile here are a couple of things to check.
Make sure that U4 is a 78L05. It looks like a transistor and is easy to mix up.
If you are using a wire antenna, make sure that R18 is installed. I had this same problem because I left R18 out intending to use a base loaded antenna. Forgot about it when I used the wire. The audio was awful. When I put R18 in, the audio was excellent.
Try different combinations of S5 settings and adjust C5 for max T1 volts. With a wire, mine runs about 3 volts, and the audio is fine. I noticed on my unit that the S5 settings were not the ones listed in the setup table. I had to try several to get the max voltage.
Neil
Total posts : 45366R18, of course! I feel like an idiot. Indeed I eventually intend to get the base loaded antenna on the SStran site, but I’m only using the wire now. Once I get home tonight I’ll try that. Thanks.
I got alot of good ideas. Problem is, most of em suck.
George Carlin (WINO)
Total posts : 45366Hi,
Here’s a hint that you can consider. If you intend to remove R18 or change C25 later, mount them about 1/4 to 1/2 inch above the board and then solder them. When you want to remove them later, just clip the leads off on the top side of the board and reheat the solder connections. The leads will come out easily without damaging the board. The effect of long leads at this frequency is negligable and besides you are tuning them out with C5.
It is a lot harder to remove a part that is stuffed down on the board than one where you can cut it out before unsoldering the leads. Always sacrifice a part if you have to to save the board. I have done this with IC’s. Clip the leads then remove them one at a time. I have never ruined a board doing this. I have ruined boards by trying to heat all 14 pins at once and pull the IC. Unless you have specialized equipment this just doesn’t work.
Let me know how it works. Just a reminder, don’t go for range before you go for quality of the signal.
Neil
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