| Author |
Message |
    
Alabamakid
New member
Username: Alabamakid
Post Number: 1
Registered: 1-2005
| | Posted on Sunday, January 30, 2005 - 2:06 pm: | 
|
My swr is reading 3+ on all channels. I know that this indicates a short and with my ohm meter I read perfect continuity between my antenna and my tool box. If I unplugged the co-ax from either the radio or the antenna the short is gone. Also, if i put my linear in line it eliminates the short and the swr reads 1:1.1
Somehow (when connected to the radio) the center pin of my coax is shorted to the backshell of the connector. I know that the coax is good, not only have I checked it several times, I have replaced it with known good coax.
Any help resolving this problem will be greatly appreciated. I have troubleshooting this for a week and am at my wits end. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 192
Registered: 9-2004
| | Posted on Sunday, January 30, 2005 - 4:22 pm: |
|
alabamakid, is the swr at 3 or does it move the needle over to the CAL indicator. what im getting at is, if you have a dead short, when you calibrate your meter, and then switch it to SWR position, your needle will move to the same mark you calibrated the meter with. if your swr is over 3 on all channels, but not pegging the needle over to the CAL position, you just have a very mismatched swr. you say that you read perfect continuity between the antenna and your tool box. (my 102" whip is mounted to my truck bed toolbox too.) if you are touching one test lead to the antenna whip, and one to the vehicle body, you should show infinite resistance, or no connection. if you use the meg ohm scale on your volt meter you may get some weird readings, but on Rx1000 scale, you should read no connection.
RF impedence is different from electrical impedence and cant be measured with a regular volt meter. what kind of antenna are you using? how is it mounted? if the antenna is not the problem, make sure that all the coax you are using is 50ohms, some 75 ohm cable looks identical to rg8mini. and 75 ohm coax will give you around a 3 to 1 swr reading. when you say that with the linear in line, the swr is 1 to 1, where is the swr meter hooked up? into the amplifier or out of the amplifier?
give me some details and i'll tey to help.
matt |
Alabamakid
New member
Username: Alabamakid
Post Number: 4
Registered: 1-2005
| | Posted on Sunday, January 30, 2005 - 5:57 pm: |
|
Matt -- Here is what I have this far.
-The swr is not pegging the needle, it is in the middle to high red.
-I put my 102" SS whip on and the swr's are 1.2:1 on ch 20 and 1.1:1 on 1 and 40
- The coax is some I got at the local cb shop. I think it is 8X or something like that. I will have to check for sure.
- The antenna I was having so much trouble with is a wilson trucker 5000.
- The mount is a L bracket on the back to the tool box, and I am using a stainless stud mount. and a 6" spring.
- When I tested the wilson with the linear in line I tested on both sides of the linear and got pretty much the same reading. SWR was a little lower between the linear and antenna vs. between the radio and the linear. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 200
Registered: 9-2004
| | Posted on Sunday, January 30, 2005 - 8:06 pm: |
|
i wish i could be of more help, but it sounds to me like the wilson is the culprit. if your 102" whip works on that mount, with the same coax, linear, radio setup, and gives you a low swr, then you have eliminated any of them as your problem, to me, its got to be that wilson, maybe its defective. if its used, you might try to get to the coil inside and see if a solder connection has broken, ive never used one of those wilson 5000 antennas.
my only question now is: WHY IN THE WORLD WOULD YOU WANT TO RUN THE WILSON WHEN YOU ALREADY HAVE THE BEST MOBILE ANTENNA EVER MADE? a 102" whip will out perform ANY other mobile antenna out there.
matt |
Patzerozero
Intermediate Member
Username: Patzerozero
Post Number: 380
Registered: 7-2004
| | Posted on Sunday, January 30, 2005 - 10:59 pm: |
|
is it a new spring, or one being reused. either way, check the braided wire inside the spring to make sure it's still attached, not corroded over, etc.
how about the wilson-i've seen a couple have some sort of coating over the threads on the shaft going into either end of the coil, cleaned up the threads & inside the coil & swr's went down.
my wilson 2000 need a LONGER stinger to get swr's to lower. only thing i had around was a bit too skinny, but another inch got swr's down. put original stinger back in & unscrewed shaft til it was in by only a few threads, retightened it & it was fine.(my astatic 3kl needed 1&1/2 inches cut off.go figure) |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 202
Registered: 9-2004
| | Posted on Sunday, January 30, 2005 - 11:19 pm: |
|
my only experience with wilsons is the lil wil i bought for my dad. we had to cut about 3/4" off to get the swr to 1.5 across the band.
matt |
Alabamakid
New member
Username: Alabamakid
Post Number: 7
Registered: 1-2005
| | Posted on Monday, January 31, 2005 - 8:03 am: |
|
The spring is one that I have had for a while. I am going to replace it. I am also going to replace the coax.
I have checked continuity on the antenna (wilson) from the stinger to the threads and the coil appears to be fine.
I have also replaced the stinger with a longer one. I think I increased the length 8-10 in.
I have also replaced the 5" shaft with a 10" shaft.
The antenna system checks out fine as long as the coax is not plugged into the radio. When I plug it into the radio my antenna shows continuity with every ground on the truck, including the neg batt post. If I un;ug the coax from the antenna, the center pin shows continuity with all grounds. This leads me to beleive that the antenna system is in good working order.
I know it sounds like a coax short, but I have tested three different pieces of coax. (the center pins are not shorted to the back shell) and I get the same result with all three when I plug them into the radio. |
Tech808
Moderator
Username: Tech808
Post Number: 4700
Registered: 8-2002
| | Posted on Monday, January 31, 2005 - 8:38 am: |
|
Alabamakid,
Try clicking on the link below:
http://www.wilsonantenna.com/support.htm
Hope this helps,
Lon
Tech808
CEF808
N9OSN |
Pig040
Advanced Member
Username: Pig040
Post Number: 663
Registered: 7-2003
| | Posted on Monday, January 31, 2005 - 10:36 am: |
|
I had one wilson where I had to get the extra long whip to make it work, it was a 5000 magnet mount. I could just not get it to match with the whip that came with it.
RIch |
Patzerozero
Intermediate Member
Username: Patzerozero
Post Number: 388
Registered: 7-2004
| | Posted on Monday, January 31, 2005 - 10:56 am: |
|
forget the amp & jumper for now.
were you using the spring with the 102" whip? if yes that'll eliminate the spring.
are you using the same mount with the wilson as with the 102? if yes that'll eliminate the mount.
are you using the same coax with each antenna? if yes that'll eliminate the coax.
all that is left to be a problem is the wilson...
did the amp work ok with the 102 whip? if yes that eliminates the amp & jumper...back to that darned wilson...
as for your statement,'Somehow (when connected to the radio) the center pin of my coax is shorted to the backshell of the connector. I know that the coax is good, not only have I checked it several times, I have replaced it with known good coax' is the coax center pin shorted to the backshell of the connector- 0 ohms on a multimeter, with the coax just hanging out & not connected to antenna, if so that shows the problem to be at the radio's s0-239 end of the setup-again double check coax pin to outside of connector while having somebody push & pull on each connector to make sure there's no loose strands of braid-all with the coax completely disconnected from everything. if that's good, check center hole of so239 on radio to threads on so239. if that's good, hook coax to antenna, but not to radio & check the same way.
could be connection at radio, but sounds like antenna.
put all of original pieces of wilson back together, longer shaft should result in shorter stinger & vice versa.
if all that fails to locate the problem, that's when i break out the hammer.... |
Alabamakid
New member
Username: Alabamakid
Post Number: 8
Registered: 1-2005
| | Posted on Monday, January 31, 2005 - 10:43 pm: |
|
Patzerozero
I used the same everything with both antennas (mount, coax, linear, jumper coax and spring)
This afternoon I checked the centerhole on the back of the radio with the threads and they are shorted together. Is this something that is an easy fix or do I need to take it somewhere and have it done? |
Ferd1605
New member
Username: Ferd1605
Post Number: 8
Registered: 1-2005
| | Posted on Tuesday, February 01, 2005 - 4:27 am: |
|
Could be a case of the Wilson needing a better and bigger ground . You never said anything about the recive , if you can not hear anything , ya gotta problem , if it is just the swr's , try a grounding strap {at least 1 inch wide } to the truck bed . make sure where you connect the ground is free of rust and paint . i also sudjest braid to the cab and frame . the key to a good system is a good RF ground .
|
Patzerozero
Intermediate Member
Username: Patzerozero
Post Number: 394
Registered: 7-2004
| | Posted on Tuesday, February 01, 2005 - 6:18 pm: |
|
hmmm, ok, sort of, NO combination of antenna/coax/amp/jumper etc should show good swr's if that is the problem. IF that is the problem, the so239 on radio center-threads shorted, a direct short to ground, the cause is probably just from changing the coax at the back of the radio so many times while working on the new antenna setup and in frustration of not getting a good match you put a bit too much stress on it & the insulator cracked...either way, if you're sure that's the problem it's a simple fix. just pick up a new so239, if the old one is popriveted in, just drill out the center of the rivets, watching for debris that drops inside(if it's already bolted, you're good, too), unsolder the center pin inside the radio, there may be a seperate ground on back of connector, or not, just see what else is attached to it, remove it, replace the new so239 with bolts, & resolder/connect anything else & you should be good!
one quick afterthought-disconnect everything from the back of so239, inside radio, so connector is free & only attached to chassis & double check w/ohmeter wiggling pin as you go just make sure it is connector & not something inside radio, after connector, follow lead from back of center pin & look for any breaks or burn marks, due to high swr, poor connection/solder joint, etc.
good luck! |
Alabamakid
New member
Username: Alabamakid
Post Number: 9
Registered: 1-2005
| | Posted on Tuesday, February 01, 2005 - 6:50 pm: |
|
Ferd1605--the tool box is grounded to the bed with a 4ga baterry cable. The bed is ground to the frame with a 4 ga battery cable. The bed is grounded to the cab with a 12" ground strap. The hood is grounded to the firewall with a 12" ground strap. The altenator housing is mounted to the frame with a 8 ga wire with gold connectors on the ends. I think I have the RF grounded. My recieve is great and I have no noise from the enginge, plugs, wipers, altenantor or fuel pump.
Patzerozero--thanks for the procedures for replacing the connector on the back of the radio.
Maybe I will get this thing fixed soon and I will be modulating with some of you guys. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 206
Registered: 9-2004
| | Posted on Tuesday, February 01, 2005 - 9:06 pm: |
|
i dont mean any offense, but why are you so fixated on getting that particular wilson 5000 to work? |
Alabamakid
Junior Member
Username: Alabamakid
Post Number: 10
Registered: 1-2005
| | Posted on Wednesday, February 02, 2005 - 6:22 am: |
|
None Taken--At first I was just trying to get it to work because it is a little more low profile than the 102". Now it is more of a matter I want to get it to work because I can't.
It has already been a good learning experience for me. I have had a CB in my truck since I was 18 (27 now) and in the past I had always just put them in and ran it. I had never bothered with swr's, proper grounding or anything like that. Between researching proper installation and troubleshootin on the web and trying different things I feel I have already increased my knowledge 10 fold.
But the ansewer to your question is: because I can't. I just want to know why it will not work with the set up that I have. |
Sg569
Member
Username: Sg569
Post Number: 74
Registered: 12-2004
| | Posted on Wednesday, February 02, 2005 - 12:11 pm: |
|
alabama, yer almost as bad as me, I wanna make that confound thing work! and nobody can stop me!
So seeing as you can't stop me, why not help me?!!!
lol |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 207
Registered: 9-2004
| | Posted on Wednesday, February 02, 2005 - 4:37 pm: |
|
i completely understand! sometimes i'll even take something that already works and break it trying to make it better.
matt |
Alabamakid
Junior Member
Username: Alabamakid
Post Number: 12
Registered: 1-2005
| | Posted on Friday, February 04, 2005 - 7:41 am: |
|
Me to Kid vicious -- I have broken plenty of things that were in perfect working order before I gotta hold of them. This use to burn my dad up. Dad was a carpenter and he would get upset when I would tinker with his tools. He never did mind if i "used" them, but a lot of times I would carry it to far. I plugged his saw into a 220V outlet one time just to see what would happen. That thing ran like a scalded dog for about 12-15 sec. Needless to say he had to buy a new saw and I had to do a lot more work around the house for a while |
Alabamakid
Junior Member
Username: Alabamakid
Post Number: 13
Registered: 1-2005
| | Posted on Friday, February 04, 2005 - 7:45 am: |
|
Have any of you ever heard this? It didn't sound right to me. I was told by a guy the other day that on a wilson you should not be able to read continuity between the stinger and the shaft (across the coil)
Doesn't make sense to me. I ask him, well if there is no continuity across the coil how does the signal get down to the coax, jump?
He said something about an internal ground in the coil. Not sure exactly what he said, I think I had squelche him out by that point. |
Tech808
Moderator
Username: Tech808
Post Number: 4744
Registered: 8-2002
| | Posted on Friday, February 04, 2005 - 8:40 am: |
|
Alabamakid,
Check out the link below for testing Wilson Antennas.
http://www.wilsonantenna.com/support.htm
Hope this helps,
Lon
Tech808
CEF808
N9OSN
|
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 208
Registered: 9-2004
| | Posted on Saturday, February 05, 2005 - 3:38 am: |
|
maybe that antenna is capacitively coupled.
matt |
Alabamakid
Junior Member
Username: Alabamakid
Post Number: 25
Registered: 1-2005
| | Posted on Wednesday, February 16, 2005 - 7:27 pm: |
|
I figured it out the day that I replaced the darn thing. The whip was about 5 inches to long and that had the SWR ran up in the red on all channels. I still haven't gotton rid of the noise yet. |
Patzerozero
Intermediate Member
Username: Patzerozero
Post Number: 461
Registered: 7-2004
| | Posted on Thursday, February 17, 2005 - 8:42 am: |
|
COAX |
Alabamakid
Junior Member
Username: Alabamakid
Post Number: 26
Registered: 1-2005
| | Posted on Thursday, February 17, 2005 - 10:05 am: |
|
I haven't found anywhere around here that sales a real good Coax. As soon as I find some I am going to buy it. |
Mrbigshot
New member
Username: Mrbigshot
Post Number: 9
Registered: 2-2005
| | Posted on Thursday, February 17, 2005 - 10:50 am: |
|
why dont you order some? i just ordered 150' of rg8u and it took 2 days to get here. cheapest i could find as well. not bad for a trip to minnesota |
Tech808
Moderator
Username: Tech808
Post Number: 4887
Registered: 8-2002
| | Posted on Thursday, February 17, 2005 - 10:58 am: |
|
Alabamakid,
Like Mrbigshot said above try the link below and order your coax from Copper with the Lowest price.
COAX
It will save you a lot of time looking and you can order exactly what you want.
Hope this helps,
Lon
Tech808
CEF808
N9OSN |
Alabamakid
Junior Member
Username: Alabamakid
Post Number: 27
Registered: 1-2005
| | Posted on Thursday, February 17, 2005 - 6:18 pm: |
|
Thank you Lon, I appreciate it. |
Alabamakid
Junior Member
Username: Alabamakid
Post Number: 29
Registered: 1-2005
| | Posted on Friday, February 18, 2005 - 6:26 am: |
|
I am using RG 8X, what Coax is considered the best? My coax is made by Belden and is 97% shielded. Is the coax from copper the absolute best that I can buy? |
Tech808
Moderator
Username: Tech808
Post Number: 4901
Registered: 8-2002
| | Posted on Friday, February 18, 2005 - 9:33 am: |
|
Alabamakid,
From my personal experience of being in the radio business for over 30+ years I used to only handle belden coax.
About 27 years ago Belden had a major price increase which I really could not understand so we switched to SIW (Superior Insulated Wire) Coax.
It was much lower in cost and the quality & performance was the same.
SIW Coax which is what copper carries is made by the OLDEST Coax manufacturer in the US.
Belden is 97% shield and SIW is 95%
I personally have never noticed any difference in performance between the two to justify the extra cost of using Belden.
We have been in the radio business for well over 30 years and we have never had 1 single compliant from anyone who has purchased SIW Coax from us after we switched from Belden to SIW Coax.
I have also never seen a single complaint / post from any of the Copper Forum members who also use the SIW Coax.
We still go thru roughy 1000' of Mini 8 and between 1000 and 2000' of RG 8 & RG 213 every couple of months for people.
RG8X Mini is rated at 1000 watts max
RG8 is rated at 2000 watts max
RG213 is rated at 5000 watts max
I personally suggest people to use RG213 and it saves them from having to upgrade or replace coax in the future if they decide to run higher powered equipment.
The choice is your's to make.
Get the coax that will fit your needs for power and price.
Hope this helps,
Lon
Tech808
CEF808
N9OSN
|
Alabamakid
Junior Member
Username: Alabamakid
Post Number: 30
Registered: 1-2005
| | Posted on Friday, February 18, 2005 - 3:58 pm: |
|
That cleared it up for me, thanks. |
Mrbigshot
Junior Member
Username: Mrbigshot
Post Number: 16
Registered: 2-2005
| | Posted on Saturday, February 19, 2005 - 12:19 am: |
|
i know the rg8u i got works great, 1.1 match with about 75 feet. no rfi at all and very low noise, my radio is sitting here just above the 0. made a very silent contact 27 miles away on am. i could barly hear him but he could hear me. all on 3 1/2 watts |
