Wierd SWR readig after coax upgrade.

[Work Life]

Hi everyone. I am new to this sight and this will be my first post. I have been getting back into the CB hobby about the past year now. I will start off by listing my equipment. Galaxy 959 ran on power supply using as base station, home brew 1/4 wave GP mounted on a mast and attached to the eve of the house (GP radials are about 2 feet above roof line), and 18' of cheap truck stop coax. Been running this setup for about 6 months. SWR readings 1.5:1 on the built in 959 meter and 1.4:1 on external meter (Astatic PDC2) using 3' coax between radio and meter. Recently I purchased 30' of Times Microwave LMR-400. I needed the additional coax length so my radio location could be more practical and I spent the extra few dollars for a high quality coax. But now I have a problem, and I need some advice. With the new coax installed and connected straight to the radio the internal 959 SWR meter is off the charts past 3:1. When I put the PDC2 meter inline it reads 1.3:1 and while leaving it inline the the internal 959 meter will also read 1.3:1 so I am not really sure what is going on. Anyone experienced something similar before?

 

[Crawdad]

Did you install the PL259's on the new coax or were they pre-installed? Either way you should use a VOM to check for shorts/opens between center conductor and ground and for continuity from end to end.

Cudos for homebrewing your GP.

73

 

[Work Life]

They were pre-installed. I will check it with VOM when I make it home this afternoon. I will let you know how it goes.

Thank you for your advice.

 

[bob85]

make sure the rigs antenna socket has not been spread by a plug with too much solder on it causing a bad connection with a properly soldered plug.

 

[Crawdad]

I will check it with VOM when I make it home this afternoon.

IMO, always a good idea to check any "new" coax or jumper before the first key-up. bob85's idea is a good one, also might check your GP feedpoint SO239 if applicable.

73

 

[Handy Andy]

Recently I purchased 30' of Times Microwave LMR-400. I needed the additional coax length so my radio location could be more practical and I spent the extra few dollars for a high quality coax. But now I have a problem, and I need some advice. With the new coax installed and connected straight to the radio the internal 959 SWR meter is off the charts past 3:1. When I put the PDC2 meter inline it reads 1.3:1 and while leaving it inline the the internal 959 meter will also read 1.3:1 so I am not really sure what is going on. Anyone experienced something similar before?

See below...

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Yes, the coax center pin, your antenna jack on the back of the Radio - is getting too "reamed out" and now can't properly connect that center lead to the pin of the coax's PL259.

Add a dollop of extra solder to "extend, enlarge and lengthen" that center pin to make sure it "seats" into yuor radios own SO-239 and the tangs on the RING seat - those little tabs, mesh well into the SO-239's connector to make sure the SHIELD and CENTER PIN are both firmly connected.

Also check to make sure your radios internal wire to that center pin feedthru of that SO-239, is still soldered to the center pin seat of the antenna jack.

Your PDC is making this connection for you and is now why you have a low SWR but a complex mess of jumpers adding a loss to your system.

 

[W4KVW]

Hi everyone. I am new to this sight and this will be my first post. I have been getting back into the CB hobby about the past year now. I will start off by listing my equipment. Galaxy 959 ran on power supply using as base station, home brew 1/4 wave GP mounted on a mast and attached to the eve of the house (GP radials are about 2 feet above roof line), and 18' of cheap truck stop coax. Been running this setup for about 6 months. SWR readings 1.5:1 on the built in 959 meter and 1.4:1 on external meter (Astatic PDC2) using 3' coax between radio and meter. Recently I purchased 30' of Times Microwave LMR-400. I needed the additional coax length so my radio location could be more practical and I spent the extra few dollars for a high quality coax. But now I have a problem, and I need some advice. With the new coax installed and connected straight to the radio the internal 959 SWR meter is off the charts past 3:1. When I put the PDC2 meter inline it reads 1.3:1 and while leaving it inline the the internal 959 meter will also read 1.3:1 so I am not really sure what is going on. Anyone experienced something similar before?

I would not care what the internal meter is reading since they are adjustable inside the radio & an external meter should be inline at all times.Never go by what the built in SWR Meter says.Even if it's close sometimes it's not reliable.

SIX-SHOOTER