| Author |
Message |
    
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 386
Registered: 4-2006
| | Posted on Sunday, May 27, 2007 - 12:08 am: | 
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This is killing me. I am pulling my hair out. As some of you know, I grounded the hood of my van, and thought that was the cause of my SWR increase. But when I ungrounded the hood, bringing my setup back to its original condition, my SWR's are still up there.
I tried changing my coax. replacing the spring. changing the mount. grounding and ungrounding other things. Disconnecting the 2nd post of the battery (It's a dual post optima red.) and simply running all negatives to the frame of the van. I tried different antennas. I don't know what else to do. With my double coil predator, the lowest SWR is 2:1. With a single coil, the lowest I can get is 1.7. I had them both flat at 1:1 before this. Any advice on why my SWR's would go high out of the blue? And yes, I tried different radio's, different meters, direct connection fromt he antenna to the radio, etc.... |
Marconi
Advanced Member
Username: Marconi
Post Number: 721
Registered: 11-2001
| | Posted on Sunday, May 27, 2007 - 1:34 am: |
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Did you check the feed line for some failure? |
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 387
Registered: 4-2006
| | Posted on Sunday, May 27, 2007 - 9:46 am: |
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Yes. I even changed it to yet another new coax line. I tried plugging direct. With a meter. Without a meter. Different lengths. Different radios, etc... |
Dale
Advanced Member
Username: Dale
Post Number: 903
Registered: 12-2002
| | Posted on Sunday, May 27, 2007 - 9:46 am: |
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try another location for doing swrs.ya already said ya tried different meters can ya get/use
a anylizer?ya are doing it with all doors/hood
shut right
dale/a.k.a.hotrod
cef426
cvc#64
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3755
Registered: 7-2004
| | Posted on Sunday, May 27, 2007 - 10:46 am: |
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i think i mentioned this before....have you tried adjusting the coils on the antennas? spread them, space them, center them outside the shaft, etc. you WILL see the swr's change by doing that to any open air coiled antenna, if the space difference is significant. |
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 388
Registered: 4-2006
| | Posted on Sunday, May 27, 2007 - 1:02 pm: |
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I tried 3 locations. Yes, all the doors closed, etc... I tried spreading the coils, centering them, etc... Not really a big change. The single coil is tuning better than the double as expected. But still way off than what it was. The only other thing I can think of is that by adding the hitch, it has somehow caused my SWR's to go like this. But I don't see how. Also, if I remember correctly, my SWR's were fine after adding the hitch. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3756
Registered: 7-2004
| | Posted on Sunday, May 27, 2007 - 1:39 pm: |
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any possibility of corrosion between the mount/sawblade/roof?
you tried different mobile antennas? what did you try & what swr did you get with them?
do you have an ohmmeter? check the mirrors & see if they are grounded to the frame of the van. if yes, get a mirror mount & try any adjustable antenna on there to what kind of swr you get. chevy inserts the mirror's mounting bolts into a bushing, sometimes it is metal to metal & things are good, some bushings are all plastic & this won't work.
as a last resort, we're going to have to see if we can get an analyzer on it to see where things are. |
Dale
Advanced Member
Username: Dale
Post Number: 910
Registered: 12-2002
| | Posted on Sunday, May 27, 2007 - 4:31 pm: |
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any possible chance water got inside the antenna?
sounds kinda dumb but felt like a should ask.
has it rained lately or ya wash your vehicle lately.if so i think id check.other than that
im with pat on the ohm meter.
dale/a.k.a.hotrod
cef426
cvc#64
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Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 391
Registered: 4-2006
| | Posted on Sunday, May 27, 2007 - 8:12 pm: |
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I'll try the mirror thing. but the problem is that everything was flat uop until a few weeks ago. So something has caused it to change. I'll check the corrosion between the saw blade and roof. I simply sanded the underside of the roof and put the saw blade there during the install. This was about 1 year ago.
If it is corrosion, I'll move the saw blade back and sand the roof again, but what should I put between the blade and the roof to prevent corrosion? |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3759
Registered: 7-2004
| | Posted on Sunday, May 27, 2007 - 9:28 pm: |
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'noalox' from home depot electrical dept. a few bucks for a small tube. |
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 392
Registered: 4-2006
| | Posted on Sunday, May 27, 2007 - 10:01 pm: |
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Is noalox conductive? In other words, if I put it on between the blade and the sanded roof, will the blade and roof still have good conductivity with each other? Thanks./ |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3761
Registered: 7-2004
| | Posted on Monday, May 28, 2007 - 3:44 pm: |
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Description:
Noalox is an anti-oxidant and anti-seizing compound that improves the efficiency and service life of aluminum electrical applications. The compound contains suspended zinc particles that penetrate and cut aluminum oxide as well as a carrier material which excludes air and prevents further oxidation. Noalox also provides additional inner-strand and inner-conductor current paths for improved conductivity and cooler connections. It reduces galling and seizing on aluminum conduit joints and promotes good ground continuity. Noalox can be used on all types of pressure-type wire connectors including screw-on, tap, service entrance and split bolt.
noalox is made for aluminum to aluminum connections, to prevent oxidation & keep the metal to metal contact 'pure'. its description also includes copper wire to copper/bronze connections. i have been looking for a comment from the web on exactly why it will work on steel to steel & steel to aluminum connections, but, i can't find it anymore. i BELIEVE it said it worked pretty much the same way as luminum to aluminum, but, no matter what, you want to make sure it is sealed in so it cannot be washed out by water, condensation, etc. google 'noalox'. |
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 393
Registered: 4-2006
| | Posted on Monday, May 28, 2007 - 8:27 pm: |
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Cool. As a matter of fact, I was thinking of re-mounting my antenna towards the rear of the roof so I don't have to always lift my self up and crawl to the center every time to take off my antenna.
I know it will be more directional that way, but what the heck. Only problem is, there is no horizontal beam that far back. Aside from calling in a welding guy to retrofit a horizontal steel beam, what can I do to re-inforce this mount and saw blade? I was thinking screwing in a long piece of 2x4 on the inside. Any thoughts? |
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 394
Registered: 4-2006
| | Posted on Tuesday, May 29, 2007 - 5:04 pm: |
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Went to Home Depot. No luck on Noalox or Penetrox. Not even Lowes had it. Any other places? Thanks. |
Tech808
Moderator
Username: Tech808
Post Number: 13792
Registered: 8-2002
| | Posted on Tuesday, May 29, 2007 - 5:16 pm: |
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Jameslarsen,
Check your local phone book for Electric Equip & Supplies or go to www.google.com and enter Pentrox or Noalox
Lon ~ Tech808 ~ N9CEF
CEF#808 ~ CEF HAM#33 ~ CVC#002
Tech808@copperelectronics.com
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3765
Registered: 7-2004
| | Posted on Tuesday, May 29, 2007 - 6:23 pm: |
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James, which home depot did you try? i KNOW for a fact it is in commack/rt25, smithtown/crooked hill rd, deer park/commack rd, selden/rt25, setauket/pond path, both patchogues....in both the tube & the small jar. it is in the ELECTRICAL dept, either near klein tools/fishtapes, or on the rack with the small electrical ends, wirenuts, etc....
as for antenna mount, you could replace sawblade with a larger piece of 1/8" or 1/4" plate, say 12x12, 12x18, 18x18 etc. HD sells 1/8" flat aluminum bar. may be able to do something with that. |
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 395
Registered: 4-2006
| | Posted on Wednesday, May 30, 2007 - 3:16 pm: |
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I tried a different Home Depot. No problem. I finally found it. Home Depot sells Aluminum that is 12 x 12? Or just in bar form (Say maybe 3 to 4" wide)? Aluminum wouldn't break after awhile from the bending back and forth? I like the saw blade that I used last time, but man, what a pain to drill holes through it (Steel). Ruined alot of bits. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3766
Registered: 7-2004
| | Posted on Wednesday, May 30, 2007 - 4:40 pm: |
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GOOD!
you have to check what each HD has in the way of 'metal'. check the yellow pages under 'sheet metal', 'iron works', etc, you may find a place locally that will cut & sell you a piece of 1/8"-1/4" plate steel in whatever size fits between any ribs/curves in your roof the best. maybe 8"x16", whatever. go 1/8", & put the sawblade UNDER it, so you can still see it from the inside! |
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 396
Registered: 4-2006
| | Posted on Thursday, May 31, 2007 - 6:04 pm: |
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Well, my Home Depot stinks. Anyway, I am going with a hockey puck mount this time. And I am again going to be using the saw blade as a backing aupport. I had to bring the saw blade to a machinist to have them cut the 2" center circle for the hockey puck mount. Man this saw blade is tough to cut through. Anyway, I figure between the hockey puck mount, and a saw blade, going through a horizontal beam along with the regular roof metal, should be a nice heavy duty, no sway mount. We'll see. I am almost done. I will post pictures.
PS--It is in the back further, so I will be more directional, plus I will be able toi disconnect the antenna more easily now instead of having to crawl to the center of the roof. |
