| Author |
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Alsworld
| | Posted on Monday, September 30, 2002 - 3:28 pm: | 
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My Lincoln has just recently developed a receive problem. The receive will cutout for about 5-8 seconds then cut back on. When it cuts out, it drops the incoming signal and volume to about half (just like I turned the volume way down) but the signal strength will go down as well. I can still hear the conversation but at very weak volume, then it kicks back in as normal.
This Lincoln is run as a base station with an Alinco 30A power supply. When it does this, I have set up the SWR's trying to see if things will change while transmitting. I cannot see in any of my meters where the SWR rises or I am losing anything strength/modulation wise when transmitting.
For what it's worth, my antenna has just gone through two tropical storms in the past two weeks. I have yet to check that factor out (I will later after work looking for the obvious) but would like your initial opinion. The SWR's are still at 1.2 - 1 and even during the worst of the storms, I could never see/hear any kind of breaking up (like a loose connection). This began about 3 days ago after the storms had completely subsided. It will happen on it's own even when no one is touching the radio.
Antenna is an Imax 2000 purchased from Copper in Feb/March timeframe. Coax is even newer DavisRF Buryflex.
I need your experience. Thank you.
Alsworld |
Bigbob
| | Posted on Monday, September 30, 2002 - 7:46 pm: |
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Alsworld check center fingers of all your so-239s,including your antenna. |
Alsworld
| | Posted on Monday, September 30, 2002 - 8:30 pm: |
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Thanks Bigbob, I'll do that. I did completely take down my antenna earlier and inspect the entire length, coax and connector (my job is a inspector so it just made sense being it was down). Everything looked okay and corrosion free but I treated the connector (dielectric grease) and resealed it at the antenna before putting it back up.
I will look at all remaining connectors as well. The darn thing is so intermittent. Would a cold solder suddenly arise like this? I am not very experienced in that area. Thanks again Bigbob.
Alsworld |
307
| | Posted on Tuesday, October 01, 2002 - 12:39 pm: |
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If the "S" meter drops at the same time , it is most likely the AGC circuit is max'd for some reason and not limiting. This will kill the RX at the same time kill the "S" meter. OR it could be the NB circuit. The NB circuit actually shuts down the front end for a set time while "pulsed noise" is clipped , then the RX comes back. It is done so fast that it is not noticed with the ear. It could be this as a problem as well. |
Alsworld
| | Posted on Tuesday, October 01, 2002 - 1:59 pm: |
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307, thank you for the response. Based on what you said, it sounds most likely like the AGC circuit (both S unit and volume concurrently reduced in 1/2). With that said, can you give me direction on where I should go from here or what to look at? Is there a "typical" cause for this?
I guess I'm asking is this a common problem in radios that I could fix myself. I'm sure I can find the schematics on the internet. I'm fairly stupid with in-depth electronics but I really want to learn and strengthen that weakness.
Thanks
Alsworld |
Alsworld
| | Posted on Tuesday, October 01, 2002 - 9:18 pm: |
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And of course now that I post this, the radio has worked perfectly for hours today. Not one hiccup. Man I hate ghost gripes. Sure wish I could duplicate it on demand then isolate from there.
Alsworld |
Bigbob
| | Posted on Wednesday, October 02, 2002 - 10:19 pm: |
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Bang the thing on the desk a few times,lol. |
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