LeoG Posted February 3 Author Report Posted February 3 I have no adapters in my house system other than the ones on the SWR meter 239>N. I do have a PL239 to Male N 90º on my repeater system to allow the coax to get to the back of the repeater. I'm over 90% confident there is water in a fitting or coax then when it freezes negates the problem of the water. It's 40ºF right now but I'm at work so I can't test it. It's not going below freezing tonight I believe so the SWR is likely to be at 2.09 again when I get home. Contacted the wife and it sounded better than I thought it would being as warm as it is. So maybe I'll be proved wrong. I'm doubting it though. Quote
LeoG Posted February 5 Author Report Posted February 5 So weird. 21ºF seems to be the magic number, or so I assume. That's when it happened when I was monitoring it. And last night I was monitoring it because the temps were suppose to fall also. But by the time I went to bed at 1am the temps had only gotten to 24º and the SWR remained at 2.06. The coax had more than enough time to freeze since it got below freezing about 6pm and was dropping about 1º per hour. It hit 21º about 5am. I wasn't up to see that but when I did check about 8am (20º) the SWR was at 1.16. The lightning arrester is near the entry point of the house so maybe the warming effect of the coax in the house is slowing the freezing down. The attic isn't heated so it's not like the cable is 65º on the other side of the wall. And there's no guarantee the issue is at the lightning arrester and not the antenna. Just more to the mystery. Quote
SteveShannon Posted February 5 Report Posted February 5 9 minutes ago, LeoG said: So weird. 21ºF seems to be the magic number, or so I assume. That's when it happened when I was monitoring it. And last night I was monitoring it because the temps were suppose to fall also. But by the time I went to bed at 1am the temps had only gotten to 24º and the SWR remained at 2.06. The coax had more than enough time to freeze since it got below freezing about 6pm and was dropping about 1º per hour. It hit 21º about 5am. I wasn't up to see that but when I did check about 8am (20º) the SWR was at 1.16. The lightning arrester is near the entry point of the house so maybe the warming effect of the coax in the house is slowing the freezing down. The attic isn't heated so it's not like the cable is 65º on the other side of the wall. And there's no guarantee the issue is at the lightning arrester and not the antenna. Just more to the mystery. If the problem is water, it is possible that it’s a weak solution with some contaminant. That would depress the freezing point. Or maybe it’s not water but some physical change, a contraction of some component along your feed line that results in a change in impedance somewhere. Do you have a dummy load you could use to isolate portions of your feed line to see where the issue is taking place? Quote
LeoG Posted February 5 Author Report Posted February 5 Of course I do. But I'm not tearing my system up until it gets warmer out. I might have the opportunity to heat up the lightning arrester and fittings to see if the SWR moves when I thaw the water in that connection if it even exists there. If nothing happens it's at the antenna. I'm tending to think that is going to be the problem area because the antenna fitting was wrapped on the ground and it has that aluminum shroud over it for protection. It seems like it would be the hardest to be infiltrated. While the lightning arrester is down stream and the water would flow down the cable. I have my drip loop and did what I could so the arrestor wasn't at the bottom of the run. But my bet is the issue is there if it's not a defect in my antenna. SteveShannon and WRYZ926 2 Quote
LeoG Posted February 8 Author Report Posted February 8 Ok I actually saw something. So far I've only seen it at 1.15 and 2.08, nothing in between. The other day as the temperature kept rising I saw my SWR at 1.43, 28º and then later at 1.52, 30º. Later when the temp got to 36 it was at 2.08 once again. When it's getting colder there doesn't seem to be a fall, just a sudden change over. SteveShannon 1 Quote
LeoG Posted February 8 Author Report Posted February 8 Waiting for the temps to be low and no snow on the roof. Not happening this weekend it seems. 6-10" of that white stuff coming. Quote
LeoG Posted February 15 Author Report Posted February 15 Well I finally saw it. I thought the lowering temperature sublimed the SWR but it was just a rapid decrease. I only saw one reading in between but that was enough to tell me it decreases not switches. Came home to find the SWR at 2.04 and the temp was just under freezing. At about 24.5º I checked and it was at 1.83, half hour later it was at its low of 1.15 again. At 1.83 most of the function of the radio returns. At 2.04 I couldn't hit the Holyoke repeater. I did a long key and some signal must have reached because I was able to hit it. No response from anyone so I assume no audio was transmitted from the repeater. Plus the received signal was very weak. At 1.83 I have access to the repeater and a good received signal. Same with my own repeater. Gotta find some time to heat up that lightning arrester to see if it kills my signal. SteveShannon and WRYZ926 2 Quote
tcp2525 Posted February 15 Report Posted February 15 6 hours ago, LeoG said: Gotta find some time to heat up that lightning arrester to see if it kills my signal. You might just want to remove the lightning arrester and toss in a barrel connector and see if it rules out the problem. Much quicker than screwing with it, unless you're doing it this way for a science experiment. Doubtful it's the arrester acting this way as it is either working or not unless water got inside. If you do find it to be the arrester, open it up like you're shucking oysters as we're all curious. Quote
WRYZ926 Posted February 15 Report Posted February 15 I agree that normally lightening arresters either work or they don't. But you never know. You could have some water inside it which expands enough to cause issues. The quick and easy way to trouble shoot is to just remove it like tcp2525 suggested. I have not had any issues with lightening arresters but have had 90 degree adapters go bad. Last time I had SWR issues, I tested at each location where there was a connector until I found the bad part. Quote
LeoG Posted February 15 Author Report Posted February 15 Well, it's absolutely water, because when it freezes the issue goes away. I would figure if the part was damaged by water expansion the problem would occur during the freeze when it pushed things apart. I'm leaning towards water in a connector that has some minerals or something in it that is conductive enough to short out enough to bring signal levels down enough to hamper incoming and outgoing signals. Once I get above that 2.0 SWR reception gets bad and transmission won't reach my farthest repeater. I know for a 100% fact that I have a problem at the house. I'm not sure if I have an issue at my repeater. But that was a wham bam thank you ma'am install without any connector wrapping. It's only the one antenna connection as there is no lighting arrester inline, the feed goes straight from the antenna to the repeater. There is a 90º connector at the back of the repeater but since I take my measurements after that connector and power levels seem fine I think it's OK. Quote
LeoG Posted 6 hours ago Author Report Posted 6 hours ago Well I did my experiment. It was about 28º out and the SWR was sitting at about 1.13. I took my wife's blow dryer and zip tied it to a stick and went on my shed dormer and heated up the lightning arrester and surrounding areas for a while and had my wife test the SWR and no change. Did this several times heating the arrestor for a few minutes before keying up again. More than certain it got way above freezing and no change. So that leaves the antenna or connection. Either way that means I have to wait for the weather to warm up before I can borrow the bucket truck to get up there. Not even going to do any testing. Replacing the antenna and the cable. Since it's just 25' I'll put 1/2" hardline there and make sure the new antenna is an N connector instead of thr SO239 UHF connector. Nice warm weather coming up so that means poor radio response til I get this all taken care of. SteveShannon and WRYZ926 2 Quote
tcp2525 Posted 2 hours ago Report Posted 2 hours ago 3 hours ago, LeoG said: Well I did my experiment. It was about 28º out and the SWR was sitting at about 1.13. I took my wife's blow dryer and zip tied it to a stick and went on my shed dormer and heated up the lightning arrester and surrounding areas for a while and had my wife test the SWR and no change. Did this several times heating the arrestor for a few minutes before keying up again. More than certain it got way above freezing and no change. So that leaves the antenna or connection. Either way that means I have to wait for the weather to warm up before I can borrow the bucket truck to get up there. Not even going to do any testing. Replacing the antenna and the cable. Since it's just 25' I'll put 1/2" hardline there and make sure the new antenna is an N connector instead of thr SO239 UHF connector. Nice warm weather coming up so that means poor radio response til I get this all taken care of. I'm glad you figured it out. The new setup will make you very happy. One piece of advice. Do the work in the most hostile weather possible and make sure you draw some blood. That way you are assured of having a perfect install. WRYZ926 1 Quote
WRYZ926 Posted 2 hours ago Report Posted 2 hours ago A job is not done correctly if no blood is drawn. tcp2525 1 Quote
LeoG Posted 2 hours ago Author Report Posted 2 hours ago I did all the work on the ground. Not sure where the water could have gotten in. It's wrapped with 3M 2155 Rubber Splice Tape and then electrical tape. It's covered with that aluminum tube on top of that. No idea how water could have penetrated. Other possibility is the antenna itself. SteveShannon 1 Quote
WRYZ926 Posted 1 hour ago Report Posted 1 hour ago Did you seal up the joints on the antenna and where to coax connects to it? You could also have a cut in the coax that you didn't see. Either way, you are on the right track replacing the antenna and coax. The Comet base antennas do have seals on all of the joints but I still wrap them just like I wrap all of the coax connections. Quote
SteveShannon Posted 1 hour ago Report Posted 1 hour ago 4 hours ago, LeoG said: Well I did my experiment. It was about 28º out and the SWR was sitting at about 1.13. I took my wife's blow dryer and zip tied it to a stick and went on my shed dormer and heated up the lightning arrester and surrounding areas for a while and had my wife test the SWR and no change. Did this several times heating the arrestor for a few minutes before keying up again. More than certain it got way above freezing and no change. So that leaves the antenna or connection. Either way that means I have to wait for the weather to warm up before I can borrow the bucket truck to get up there. Not even going to do any testing. Replacing the antenna and the cable. Since it's just 25' I'll put 1/2" hardline there and make sure the new antenna is an N connector instead of thr SO239 UHF connector. Nice warm weather coming up so that means poor radio response til I get this all taken care of. Good job! Yes, water could get into the antenna and migrate down into the connection. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.