Transmitter Only Sounds Good During Day

[-klb-]

I see where I got 75 ohms from. It was what he used last year.

I'm pretty sure you can't fry a FMA-200 with a 5W transmitter.

I wish I could remember what the dc resistance of the FMA-200 is. I really think he may have an intermittent or partial open somewhere in the system. For example, a faulty, or corroded barrel connector. If it is a near short, he could disconnect the transmitter, and measure through the cable. A high resistance would be a cable flaw. If the antenna is open circuit DC, he would have to disconnect both ends, short one, and measure the other.

He might do better with a 5 foot cable, and the antenna indoors. Unless he is in a metal building, or has severe topology problems, he has plenty of power to get through the walls.

[Bob Musil]

Here is what I have: http://www.radioshack.com/product/index.jsp?productId=2103483

I have a 20 foot section connected to the antenna, a connector in the attic, and a 10 foor section running to the transmitter. At the moment, the transmitter is sitting on a cardboard box about 4 feet from the computer.

Actually, we may have at least temporarily solved the problem. My brother-in-law came over this evening. With him on the roof adjusting the antenna, my wife in the car checking the radio, and me at the compiter/transmitter, we did a series of frequency checks. We finally settled on 94.1 as the best frequency.

While double-checking this, my BIL mentioned that the static sounded like over-modulation from a stereo turned up too high. I adjusted my system volume down to 30%, and most of the remaining static went away.

There are still a couple of things that confuse me. First, tuning the length of the antenna is making zero noticeable difference in the reception. Did I fry the antenna, or is the length really not that important, or ???

Second, the reception and the voulme are still pulsing between strong and week. Ant ideas what could be causing this?

[-klb-]

Antenna tuning will only affect your range, not what it sounds like within your range. No amount of antenna tuning will fix over modulation.

Also, having the clamp loose, and a person touching the antenna will totally alter the tuning.

[Max-Paul]

Right, touching the antenna will detune the antenna. But if he who is touching the antenna and starts to move things around starts to feel a tingle, then he is going the wrong way. LOL Voltage on the antenna will go up with SWR going up. Or that might be at the far end only. LOL

Right, Now if your car stereo had a S Meter like C.B.s do and you drive away till the meter is about half scale. I suppose you could adjust it some and the S meter might rise or dip to give you some idea. But then your car receiver does not have a S meter. So, back to earlier suggestion. Find a Ham Radio Op and see if he has a SWR meter that will work up to the 2 meter band.