Swr change.

[WRCC711]

I have a question, the swr on my base radio has changed after installing a UHF lighting arrestor in line on my antenna cable (rg58) at the antenna mast. It has gone from 1.5 to 2.4. I double checked my fittings ( installed pl259 solder/crimp connectors ) for continuity with my multi meter which gave me a reading of 002 . A  very slight bit of resistance . I did the same check on both sections of cable with the same readings.  The arrestor is designed for uhf, it's the gas cartridge type ,I have a ground wire ran from it to a common ground stake where several other antenna are grounded. I know an swr of 2.4 isn't the end of the world,but I'm at a loss as to the increase. 

[SteveShannon]

3 minutes ago, WRCC711 said:

I have a question, the swr on my base radio has changed after installing a UHF lighting arrestor in line on my antenna cable (rg58) at the antenna mast. It has gone from 1.5 to 2.4. I double checked my fittings ( installed pl259 solder/crimp connectors ) for continuity with my multi meter which gave me a reading of 002 . A  very slight bit of resistance . I did the same check on both sections of cable with the same readings.  The arrestor is designed for uhf, it's the gas cartridge type ,I have a ground wire ran from it to a common ground stake where several other antenna are grounded. I know an swr of 2.4 isn't the end of the world,but I'm at a loss as to the increase. 

If you take the lightning arrester out does your SWR go back down?

[WRCC711]

2 minutes ago, SteveShannon said:

If you take the lightning arrester out does your SWR go back down?

No,sorry I forgot to add that in, I removed the arrestor and added a coupler,nothing changed. I could try it again just to be through. 

[SteveShannon]

2 minutes ago, WRCC711 said:

No,sorry I forgot to add that in, I removed the arrestor and added a coupler,nothing changed. I could try it again just to be through. 

If the SWR doesn’t go back down when you remove the arrester, the problem isn’t the arrester. You either have a bad connector, cable, or antenna. Swap each piece out individually until you isolate the problem. 

[Socalgmrs]

I’d start with the rg58 it may have gone bad internally when you messed with it. 

[WRCC711]

10 minutes ago, WRCC711 said:

No,sorry I forgot to add that in, I removed the arrestor and added a coupler,nothing changed. I could try it again just to be through. 

So I retried removing the arrestor and retesting. I went down to swr 2 , I then reattached the arrestor and and re tested with an swr of 2.3

[WRCC711]

11 minutes ago, SteveShannon said:

If the SWR doesn’t go back down when you remove the arrester, the problem isn’t the arrester. You either have a bad connector, cable, or antenna. Swap each piece out individually until you isolate the problem. 

I did test the continuity of both the connections as well as cable,I did suspect a short. As I said I had a reading of 002 which shows the smallest bit of resistance. If need be ill replace  the rg58 with two pre-made lengths ,maybe upgrade from the rg58. My current swr is now 2.3

[LeoG]

At least it's not water infected like mine got.  I went from a 1.15 to a 2.08 and reception and transmission were affected substantially.  Under 26ºF everything went good.  As soon as it went over freezing it went bad.  After the cold weather went away so did my reception and transmission.  Replaced the bad antenna and coax section got swapped over to Heliax.  Great stuff.

Good luck with solving your issue.  It's never fun when it happens and you can't figure out why.

[RayDiddio]

37 minutes ago, SteveShannon said:

If the SWR doesn’t go back down when you remove the arrester, the problem isn’t the arrester. You either have a bad connector, cable, or antenna. Swap each piece out individually until you isolate the problem. 

Going to agree with Steve on this. Given everything other reply from OP it seems as though either the connector didn't go as well as thought (the multimeter test doesn't show as much as a VNA does) or something is wrong with the coax.

Age of the coax? I may have missed this. 
How long has it been outside?
Have you sealed the connectors against the weather?

Almost sounds like the connectors are the source, but that is just from antenna building experience as when all else fails, it's almost always the connector.

[SteveShannon]

17 minutes ago, WRCC711 said:

I did test the continuity of both the connections as well as cable,I did suspect a short. As I said I had a reading of 002 which shows the smallest bit of resistance. If need be I’ll replace  the rg58 with two pre-made lengths ,maybe upgrade from the rg58. My current swr is now 2.3

You don’t mention the lengths of your RG-58, but for UHF almost any length is too much, but lossy cable like RG-58 will always make your SWR appear artificially low because less forward power reaches the antenna than passes through the meter so there’s less power to reflect AND much less reflected power reaches the SWR meter after reflecting from the antenna. So although the losses in RG58 is a problem, it’s not the cause of your SWR reading higher. 
Second, although a short or an open can be detected by a multimeter, the effect of RF frequencies is completely different. Yes, detecting a short would be reason to discard a connector or a cable, but resistive losses, the 002 (I assume that’s 2 millions?) that you measured are nothing to worry about. 
Without a dummy load and antenna/coax analyzer or nanonva your best option is to simply remove a piece at a time, replacing it with a known good component. 

[WRCC711]

1 minute ago, RayDiddio said:

Going to agree with Steve on this. Given everything other reply from OP it seems as though either the connector didn't go as well as thought (the multimeter test doesn't show as much as a VNA does) or something is wrong with the coax.

Age of the coax? I may have missed this. 
How long has it been outside?
Have you sealed the connectors against the weather?

Almost sounds like the connectors are the source, but that is just from antenna building experience as when all else fails, it's almost always the connector.

The coax is less than six months old at this point,  yes yhe connectors could be the issue. I am looking at just replacing it with two pre-made lengths of RG 213/U cable. 

[SteveShannon]

Just now, WRCC711 said:

The coax is less than six months old at this point,  yes yhe connectors could be the issue. I am looking at just replacing it with two pre-made lengths of RG 213/U cable. 

I still don’t know what the length is, but rg213 still sucks for uhf. 

[WRCC711]

1 minute ago, SteveShannon said:

You don’t mention the lengths of your RG-58, but for UHF almost any length is too much, but lossy cable like RG-58 will always make your SWR appear artificially low because less forward power reaches the antenna than passes through the meter so there’s less power to reflect AND much less reflected power reaches the SWR meter after reflecting from the antenna. So although the losses in RG58 is a problem, it’s not the cause of your SWR reading higher. 
Second, although a short or an open can be detected by a multimeter, the effect of RF frequencies is completely different. Yes, detecting a short would be reason to discard a connector or a cable, but resistive losses, the 002 (I assume that’s 2 millions?) that you measured are nothing to worry about. 
Without a dummy load and antenna/coax analyzer or nanonva your best option is to simply remove a piece at a time, replacing it with a known good component. 

I agree, so ive decided to just replace it with two length of RG213/U that should be  sufficient I think. 

[WRCC711]

1 minute ago, SteveShannon said:

I still don’t know what the length is, but rg213 still sucks for uhf. 

Two 25 ft lengths, sorry forgot to add that part.

[nokones]

Your multimeter continuity reading on the coax cable should be reading "OL" meaning no resistance. Your coax has an itty bitty short, that's not good. And more than likely it is at one of the connectors. If your coax run from the radio is more than 20 feet you should be using LMR400 coax that is purchased from a reputable radio electronics supply retailer and not from an operation that specializes in cheap discount inferior products.

[WRYZ926]

RG-213 has 5.28dB/70% loss at 100 feet and LMR-400 has 2.87dB/48% loss at 100 feet. The calculations were made using 50 watts in and an SWR of 1.5. You can get away with using RG-213 but LMR-400 will definitely work better. 

Cheaper alternatives to LMR-400 is DX Engineering 400MAX or R&L Electronics Jetstream 400Flex. As @nokones stated, stay away from the cheap stuff from Amazon and eBay.

The cheaper stuff will have less ground shielding plus some use aluminum instead of copper shielding. You definitely won't get as  good of a solder joint on your connectors with aluminum shielding, if you can even get the solder to stick to it.