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Message |
    
Vanillagorilla
Advanced Member
Username: Vanillagorilla
Post Number: 925
Registered: 4-2005
| | Posted on Friday, December 22, 2006 - 11:26 am: | 
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Long story short...how can I get two different SWR readings with 4 different meters?
Resetting the solorcon'99 on a tower after a quick internal rebuild and in setting the tuning rings I see a higher SWR on 40 than on 1. Just to be sure (because its SO out of whack)I switch meters and get the OPPOSITE reading!..higher on 1 than 40.
I hook it up to the BK servicemaster and get the same as the Dosy...for a goof I hook up the MFJ when I thought I was going to trust the Dosy...well the MFJ941 tends to agree with the first meter. So there you have it...4 different meters with two different readings...equally.
The radios SWR meters (whichever I try) agrees with the BK. My question is WHY do different meters show two directly OPPOSITE readings? I don't know which to trust! AHHHH!  |
Bruce
Senior Member
Username: Bruce
Post Number: 4255
Registered: 9-2003
| | Posted on Friday, December 22, 2006 - 12:15 pm: |
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sounds like something is very reactive/cap and the meters read either way. |
Vanillagorilla
Advanced Member
Username: Vanillagorilla
Post Number: 926
Registered: 4-2005
| | Posted on Friday, December 22, 2006 - 2:30 pm: |
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Like I mentioned I had to break down the 99 to try to solve a static noise level I had for over a month. When I took the bottom apart I saw the shield pulled away from the SO239 SO I pulled out my bag of tricks and made the repair. The RG8X that went from the SO239 to the matching portion is probably a little shorter now so it kind of throws the tuning rings out of whack. I'm home now and gonna keep plugging away at it till I can possibly get it flat.
All else fails a friend gave me a loaner Army Big Stick for as long as I need. I hate to "borrow" but the funds are NOT there right now for new.
Off to the yard...I'll get back here later!
Thanks |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3432
Registered: 7-2004
| | Posted on Friday, December 22, 2006 - 6:07 pm: |
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sell a kid(less $$ to spend on presents, too  ) & get a metal antenna . maco v5/8 with proper grounding & you should see less RFI as well. some 9913f would be nice too. 'internal rebuild' may be an issue, as well. if the big stick works, then the a99 is probably ready for the scrap pile. |
Vanillagorilla
Advanced Member
Username: Vanillagorilla
Post Number: 927
Registered: 4-2005
| | Posted on Friday, December 22, 2006 - 9:27 pm: |
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get you later Bruce and thanks.
Pat...yesserie...Had no time to fool around with the 99 any longer. Decided to put the Shakespere Army in it's place and got a friend to help hoist the tower. The big stick is sitting at 40ft feed and looking good for now. The plans ARE for a aluminum antenna as soon as the snow melts.
Grounding has been addressed and IF I ever get around to posting HALF the pics I promise you'll see what I did.
Still scratching my head after seeing the SWR thingy though.
Right now the Army is fine with a 1.1:7 with the heat on across the band. I could live with that without looking back.
Just glad to be back on the air. Not sure if I eliminated the static carrier I was trying to lose but looks good right now. I have around 1-2 S units of white noise that goes up on SSB but that could be conditions or the rain this time...it wasn't there earlier.
This hobby is killing my nerves  |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2347
Registered: 9-2004
| | Posted on Saturday, December 23, 2006 - 12:24 am: |
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hank,
when trying to find that noise problem; dont underestimate the possibility that some device in your or your neighbors house might be causing it.
go check in the kids rooms for a new toy or charging device.
maybe something new in the kitchen.
my new electric shaver that cost $100 kills my radio when its plugged in. on or not.
good luck,
matt |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3433
Registered: 7-2004
| | Posted on Saturday, December 23, 2006 - 9:23 am: |
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the kids across the street have those electric powered jeeps that they drive in. the charger on 1 of them used to make an awful static. my wife had an aftermarket charger for her cell phone that made an awful pulsing sound in the radio. the eureka electric broom my wife used to have made an incredible 30 over 9 static, too. |
Tech833
Moderator
Username: Tech833
Post Number: 1553
Registered: 8-2002
| | Posted on Saturday, December 23, 2006 - 11:15 am: |
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Pat,
Changing the length of the cable inside the A99 will not change the tuning. Something else would.
Now, I am curious, do your different meters show different readings on the new antenna also?
Regular SWR meters are NOT accurate, and not to be trusted as authority. I have high-dollar SWR meters that show different readings than the Bird meter. Any little impedance difference will throw SWR meters way off, and which way they get thrown off depends on how it is designed. Even changing cable lengths can change the SWR reading if there is some reactance at the metering point. |
Vanillagorilla
Advanced Member
Username: Vanillagorilla
Post Number: 928
Registered: 4-2005
| | Posted on Saturday, December 23, 2006 - 2:25 pm: |
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Paul...I didn't think changing the coax inside the 99 should make a difference but I didn't want to rule it out. Thanks for the clarification.
I tested both antenna originally 3ft from the feed point with a W/T attached to another 3ft jumper with SWR meter in between. The MFJ941 in bypass mode showed the Army to be fine right around 1.4:1 but the 99 was nuts. I crossed with an old Archer meter which showed opposite but agreeing with the BK. The Dosy which is in the shack agrees with the MFJ.
There is not really enough variation with the Army to tell if the same may be true there but I will test it for your consideration.
HOW THIS ALL CAME ABOUT:
Going back about a month I noticed a higher than average static/ white noise in my radios...around S3 to S5 on AM and S7 on SSB. Always thought it was atmosphereic conditions and would go away. Well a month later struggling through contacts I realized it wasn't nature. I also have it in my mobile at the top of my driveway!
A neighbor who works for the cable company thought it might be the underground cable comming in from the cable box at the foot of my driveway.
He brought home a CLI meter (Cumlative Leak Index) to test for stray / leaking RF. (COOL TOY!)
Average leak detection is around "6-10" and over 20 they are required to repair immediatly as it could cause interference with local police/fire and aviation communications. Well we did the scan from where I thought the leak could have been and SHAZAM we read an RF leak at the top of my driveway pinging in at over 175 with the internal alarm going off on the 'Sniffer". We layed new RG11 from the cable box into the house and rechecked our work...very good...computer is much faster now...but the static was still in my radios!
I threw the main breaker in my house and went to the driveway to check THAT radio..still S5 static that drops to 0-1 S units as I pull out of the driveway. It's not my house....must be the cable guys! He swore he had nothing new plugged in and all was as it normally is. I've checked morning/noon and night...its ALWAYS there 24/7.
Next I called in the power co. He came by and did a quick check of all external sources while I was at work. He detected nothing out of the ordinary but did "hear something". He spoke with my wife and told me he'd be happy to come back after the holidays to help further with me...cool!
In the meantime I got my butt in gear and finished cancelling out my variables by FINALLY replaceing the OLD coax with a fresh 75' run of RG8U I bought from Copper a YEAR ago and a different antenna in a different location on a tower. I think I still have the noise but time will have to tell. If I do still have it it has gotten better at around 1-2 S units with a jump to 4 on SSB.
I should mention that it all but goes away near 28MHz...hmmmm?
In my spare time I came up with a neat little RF finder of my own. I took my old Cobra W/T and put an adapter on it to accept a PL259 to which I added a few short inches of scrap coax. I soldered a 3 ft length of wire to the conductor and wrapped it around an old police night stick (wood). I now had something to walk around with and get directional and mobile with.....boy does it get noisey going between my and my nieghbors house...gets REAL loud 2ft from HIS electric meter/box....Hmmmmmm!
I'll wait for the holidays to pass and take the LIPA guy up on his offer...then I'll show him my findings.
I get the feeling it's going to be a Christmas decoration somewhere in a nieghbors house that stays plugged in 24/7 for the last month!
Must find the source before it dissapears! |
