antron 99 RG8U SWR

[KD2GOE]

I am running a Antron 99 with RG8u I am getting 2.5:1 ch40. 2.0:1 ch1 @ 50watts
It was higher on with the ground plain.

Can I put my dummy load on at the end of the coax to test it?

1.4:1 with 4 watts

 

[Mudfoot]

Try another section of coax, if possible.

 

[Robb]

IIRC, RG8U has a urethane based insulation. It is notorious for having the center conductor deviating from the center. The net effect is a bad SWR when testing with a dummy load, as you have seen for yourself.

Think you did the right test/troubleshooting; congrats!

 

[Marconi]

Try another section of coax, if possible.

I agree m42duster, but I'm not sure I understand exactly what 396 is saying, when he asks his question. Robb may also be right, so you need to check the feed line thru-put.

396, where is the meter that you're getting you SWR readings from? Hopefully you are not using your radio's SWR meter at this point and with questions in your testing. The meter in the radio may be right, but how do your really know.

If you're using an inline meter, then put the inline meter as close to the radio as you can. Attach the dummy load with as short a connection as you have again. A direct connection would be best if you have a double female connector. This checks your radio's potential output and SWR, then record your watts and SWR.

Then put your radio to the feed line with the meter and dummy load at the far end. Check and record your SWR and your watts again. Except for a very little loss in the feed line...your results should be close to the same.

This checks you radio's output, and your feed line's thru-put.

If you're getting your SWR reading from a meter in your radio...then never mind. Again, your meter in your radio might be right on the money, and this testing should show you if your radio meter is working close to right.

 

[KD2GOE]

I did the test with the dummy load on the end of my coax it was a flat 1.0.. with the low pass filter added it was 1.1ish so my cable and coax is good.

I put my SWR meter right on my antenna with 2' of RG8x and I was getting an SWR of 2.8:1~3ish it looks like my A99 is shot.

I have not hard this antenna for more then 3 months this sucks but this is the first time I am pushing 50watts dead key though.

how is soracon with there exchanges? I am going to call them first thing tomorrow morning but I cant fined there web page... hmmmm any one out there have there phone number?


my friend has a A99 to he is going to take it down and bring it over and we are going to see if it is some thing in my back yard but he has a worse setup then me so i don't know we will see.

 

[KD2GOE]

I agree m42duster, but I'm not sure I understand exactly what 396 is saying, when he asks his question. Robb may also be right, so you need to check the feed line thru-put.

396, where is the meter that you're getting you SWR readings from? Hopefully you are not using your radio's SWR meter at this point and with questions in your testing. The meter in the radio may be right, but how do your really know.

If you're using an inline meter, then put the inline meter as close to the radio as you can. Attach the dummy load with as short a connection as you have again. A direct connection would be best if you have a double female connector. This checks your radio's potential output and SWR, then record your watts and SWR.

Then put your radio to the feed line with the meter and dummy load at the far end. Check and record your SWR and your watts again. Except for a very little loss in the feed line...your results should be close to the same.

This checks you radio's output, and your feed line's thru-put.

If you're getting your SWR reading from a meter in your radio...then never mind. Again, your meter in your radio might be right on the money, and this testing should show you if your radio meter is working close to right.

I am using a radio shack SWR meter. i know it is good i compared it to 2 others

 

[W5LZ]

Does that 'A99' have the tuning rings on it? If so, have you tried readjusting them? That's what they are for you know.
- 'Doc

 

[hotrod]

I am using a radio shack SWR meter. i know it is good i compared it to 2 others

for swr that meter is actually as good as any dosy,pdc,astatic . you say your swr
is 2.5 . what channel is this on? is there any varation on channel. check ch.1 then 40
there should be a slight difference.if not you may have a bad ground /or bad coax.
if theres a slight change then use your tuning rings to adjust it.also when doing
this i find it easier to use a low deadkey like 3-4 watts . not 50. and nothing more than
radio ,meter, antenna. ask your locals if they have a antenna anylizer these work the best

 

[KD2GOE]

Does that 'A99' have the tuning rings on it? If so, have you tried readjusting them? That's what they are for you know.
- 'Doc

yes, and it made little difference getting it lower then 2.5 on ch 40 to 1

for swr that meter is actually as good as any dosy,pdc,astatic . you say your swr
is 2.5 . what channel is this on? is there any varation on channel. check ch.1 then 40
there should be a slight difference.if not you may have a bad ground /or bad coax.
if theres a slight change then use your tuning rings to adjust it.also when doing
this i find it easier to use a low deadkey like 3-4 watts . not 50. and nothing more than
radio ,meter, antenna. ask your locals if they have a antenna anylizer these work the best

I am doing the readings at the antenna

2.5 is at CH 1
3 is at CH 40

are you saying you only need to tune it at a dead key of 4 watts??? I was told you need to have it under 1.5:1 even if your pushing 100 watts

 

[Robb]

Take the amp out of line and re-test the SWR between the radio and the antenna alone.
If it is OK; then the amp or the jumper coax - or both - are the problem area.

Doubtful - but impossible - that the A99 is the problem.

Not every amp installation is as simple as just plugging them all together.

 

[KD2GOE]

Take the amp out of line and re-test the SWR between the radio and the antenna alone.
If it is OK; then the amp or the jumper coax - or both - are the problem area.

Doubtful - but impossible - that the A99 is the problem.

Not every amp installation is as simple as just plugging them all together.

this is all with my RCI-2990

 

[W5LZ]

Couple of things here. Do any antenna tuning less the amplifier! Once the antenna is really tuned, it makes little to no difference in power being applied, unless that power is more than the antenna can handle. Once the antenna system is tuned without an amplifier then try it with the amplifier. The only thing that changes in that type of situation is the -amplifier-, not the antenna, not the feed line, just the amplifier. If there's a mismatch in impedance, higher SWR, then guess where the difference is! Not a happy thought? Sorry 'bout that, but that's the usual thing that happens. Why? Because most if not all CB amplifiers use a 'no-tune-, or 'one size fit's all' type of output impedance matching system. And like any 'one size fit's all' thingy, it very seldom ever 'fits' at all. It merely means that the output impedance of that amplifier isn't the same as the radio's. So, where should the 'change' be made to make it the same? Think about that! Do you really need that explained to you? Doesn't matter if you like it or not, that's the way it is...
- 'Doc

 

[Robb]

Do you have another radio you can test with the antenna?

 

[KD2GOE]

Couple of things here. Do any antenna tuning less the amplifier! Once the antenna is really tuned, it makes little to no difference in power being applied, unless that power is more than the antenna can handle. Once the antenna system is tuned without an amplifier then try it with the amplifier. The only thing that changes in that type of situation is the -amplifier-, not the antenna, not the feed line, just the amplifier. If there's a mismatch in impedance, higher SWR, then guess where the difference is! Not a happy thought? Sorry 'bout that, but that's the usual thing that happens. Why? Because most if not all CB amplifiers use a 'no-tune-, or 'one size fit's all' type of output impedance matching system. And like any 'one size fit's all' thingy, it very seldom ever 'fits' at all. It merely means that the output impedance of that amplifier isn't the same as the radio's. So, where should the 'change' be made to make it the same? Think about that! Do you really need that explained to you? Doesn't matter if you like it or not, that's the way it is...
- 'Doc

where the hell are you coming up with amplifier???? I am not running an after market external amp

I have preformed the test at higher then CH 40 CB and same results with my RCI 2990 and there is no need to be a dick I am trying to understand....

I first tuned it with my uniden Washington

Do you have another radio you can test with the antenna?

yes I have my uniden Washington I did the test with it at the antenna and it is 1.2:1 CH 1~40 at 4 watts dead key and 1.5 SWR at the radio my friends A99 is 1.0:1 from CH 1~40 at the radio

 

[Robb]

where the hell are you coming up with amplifier???? I am not running an after market external amp

I have preformed the test at higher then CH 40 CB and same results




yes I have my uniden Washington I did the test with it at the antenna and it is 1.6:1 CH 1~40 at 4 watts dead key my friends A99 is 1.0:1 from CH 1~40

Adjusted the rings on the antenna with the Pres Washington yet?