Swr question mobile vhf

[Se7en]

Every other day i swap mobile antennas from a sbb-5 to a diamond cr320. Iv noticed my swr is 3.2 on vhf and 1.1 on uhf with the sbb-5...the cr320 is flat swr and much older than the sbb-5. Why is my match so darn high ??? The mount is a pl with lmr-400 10' and the jumper from the meter to radio is rg8 (big stuff) @ 1.5 feet long...is it possible the one foot and a half rg8 jumper is causing problems when checking my match ? Meter is never inline except to test pw and swr every 2 months.

 

[RatsoW8]

This might be a silly question but did you tune it per the manufacturers instructions? Dual band vhf/uhf antennas are seldom perfect but you should be able to get the tuning closer that that.

 

[Se7en]

This might be a silly question but did you tune it per the manufacturers instructions? Dual band vhf/uhf antennas are seldom perfect but you should be able to get the tuning closer that that.

uh..did not come with any tuning instructions? nor has the antenna made contact with a foreign object:headbang
wheni first got the antenna it has always been 1.1 on vhf and uhf

 

[W5LZ]

Have you checked to see where it was tuned, up/down the band? When you change an antenna's environment/location you also change how it's tuned (it's relation to everything around it). That's about as normal as it get's, so some changes are normal. So, just what/how much has changed? If it was 'good' before, then I wouldn't expect a huge change, but there will always be some.
- 'Doc

 

[Captain Kilowatt]

My guess is that something has gone awry from being swapped out every other day. What is the reason for swapping out like that? Other than striking something constant mounting/unmounting of antennas is a major cause of damage to them. Check the mating contacts on it both in the base and between sections. Mobile dual band antennas rarely if ever need field tuning. If you do try and tune it ( not likely the issue as it worked great before) then remember that a little change on one band can make a BIG difference on the other band.

 

[Se7en]

My guess is that something has gone awry from being swapped out every other day. What is the reason for swapping out like that? Other than striking something constant mounting/unmounting of antennas is a major cause of damage to them. Check the mating contacts on it both in the base and between sections. Mobile dual band antennas rarely if ever need field tuning. If you do try and tune it ( not likely the issue as it worked great before) then remember that a little change on one band can make a BIG difference on the other band.

OK the reasion for the change is that where i work is a huge parking structure tallest is 8 feet or less the sbb-5 will hit and my bad it isn't the cr320 i swap to its actually a diamond 19 inch dualbander which is spring loaded that works fine swr is flat on 146mhz and 446mhz. As for the sbb-5 this is the first time iv seen 146mhz in the 3 swr range. I was told my vhf transmission was sounding scratchy and terrible than before...when using the sbb-5.
Hope all that makes since.

Fyi i have 4 differnt dualband antennas in the blazer i keep on the floorboard of the truck to swap when needed or backups or if a local needs to use one.

I guess i can just throw away the sbb-5 and buy another one ?

 

[Moleculo]

You know that comet SSB-5 folds over, right? Check the hinge where it folds to see if it's become loose. That aside, I suspect something in the base has come loose due to the constant swapping. If I were you, I'd find an antenna you like that folds over so when you park you don't have to swap it out.

 

[Se7en]

You know that comet SSB-5 folds over, right? Check the hinge where it folds to see if it's become loose. That aside, I suspect something in the base has come loose due to the constant swapping. If I were you, I'd find an antenna you like that folds over so when you park you don't have to swap it out.

Thanks for the reply Tim.
I had forgotten it folds over cause the fold.over isn't that great cause the antenna is light weight and it will not stay folded over .
Ill check the hinge. Btw the center pin is loose inside and has been even when i bought it which it didn't affect performance. Maybe there is some moisture in it..ill check it out. Honestly i wish it was spring loaded rather than foldover:thumbdown: than i wouldn't mind it hitting random things.
Might be time to go Larsen so i can piece together my own spring loaded only wish they had pl type antennas not just nmo

 

[Se7en]

Solved

Sure enough there was water inside the fold over part on the sbb5 so i took it apart as best i could and set it in a large oven and left it at 65c. let it cool than cleaned it best as i could and swr is back to 1.2 (Casual reading for swr)

 

[HD19759]

You know that comet SSB-5 folds over, right? Check the hinge where it folds to see if it's become loose. That aside, I suspect something in the base has come loose due to the constant swapping. If I were you, I'd find an antenna you like that folds over so when you park you don't have toes swap it out.

It mst depend on which version of that antenna that you get. Mine is a SSB5 NMO and it does not bend over and I know for a fact the SSB5 also does not.