OP
SWR 'Contest'
- Thread starter SSTJ
- Start date
I got the exact same SWR as @rasband using thd 520xl and a 2' firestik. Still a little bit high for my liking. I tried a 3' and was able to tune it to 1.2-1.3, so im gonna snag one and keep the 2' as a backup
OP
Intersting. I was leaning the same way until I heard that Jerry B gets his same setup down in the 1.5 range.
My only theory is that I don't have a good ground, but I don't know how to test for 'quality' of ground. Except maybe using resistance ... I wonder, if we all compared resistance (using Ohmmeter) between the outside of our coax (where it meets the underside of the mount) and our frames, whether that would explain the differences we're getting in SWR.
For now I'll keep tinkering, see if Jerry visits this thread, and see if I can borrow my friend's antenna analyzer.
Im with you on that, but heres the thing I dont understand. If my ground is bad, shouldnt my SWR be bad for both antennas then? Not just the 2'
OP
Yea, in your case, I reckon so. I only have the one antenna, so I guess it's still a possibility for me.
Might just be a bad antenna, or are they two different types of antennas? Does the 2' have a tunable tip with a vinyl cover? Are you you seeing the higher SWR after getting a low SWR with the cap off but then the SWR goes up after replacing the vinyl tip cover?
If so, the trick is to tune the antenna slightly off to the correct side of where the best/lowest SWR is so when reinstalling the vinyl cap the SWR goes down instead of up.
The vinyl tip cover affects the SWR in such a way that it's possible to detune the antenna slightly to one side of best attainable SWR so placing the cap back on brings the SWR down. This has a bit of trial and error to it but it works.
Both are the same types (to my knowledge) so that is beyond me. Both had the vinyl covers with tunable tips on them and I was getting my readings with the cap on. Not sure why that happening, but it gives me a piece of mind that a 3'
Maybe re-read what was said above a little closer as it's hard to describe what might be happening. It's possible that the tuning was done in such a way that the SWR was lower before reinstalling the cap and simply placing the cap on top of the antenna detuned it and raised the SWR higher than what it was without the cap being present.
I conpletely missed that
Lol sorry, I get what you are saying now. Ill give it another go when I get to moab(on the road right now)and if it does mean anything, I was never able to get the SWR low even without the vinyl cap on
Oh yeah that makes a difference and means it's not the cap causing the problem. One more thought. The desired dip in the SWR can happen very quickly and can missed entirely if the tuning screw is turned too far between SWR checks. The shorter the antenna the more easily its narrow point of minimum SWR tune point can be missed entirely.
OP
Well, I finally got my SWR down. After giving up for a while, I recently installed 90° connectors on the tail-light mount and also on the back of the CB. In both cases, the goal was only to redirect the coax so that I could route it more efficiently. I then tried my SWR again, and it was much higher than before. In my mind, I blamed the 90° connectors, although I don't see how that could have made a difference. More likely something else changed while the installation was settling in?
Anyway, this time the tuning process went much more straightforwardly: I lowered the tip whenever channel 40 was higher than channel 1, and vice-versa. I put the cap back on for each reading. In about 10 minutes I had readings of 1.4 on channel 1, 1.4 on channel 40, and very low (1.1 or so) on channel 20.
Thanks for all the help!
Anyway, this time the tuning process went much more straightforwardly: I lowered the tip whenever channel 40 was higher than channel 1, and vice-versa. I put the cap back on for each reading. In about 10 minutes I had readings of 1.4 on channel 1, 1.4 on channel 40, and very low (1.1 or so) on channel 20.
Thanks for all the help!
I run a Wilson 5000 and it gets to 1.5 SWR on ch 20.
I don't have any Firestiks.
I don't have any Firestiks.
I am running a 3' firestik, teraflex driver side tail light mount and uniden PRO505XL and 18' RG58-A/U. Unfortunately with my rugged ridge dash mount the coax is at a pretty sharp bend getting to the back of the radio pinned against the windshield
The best SWR I am able to achieve with my Astatic PDC7 is 1.2 on Ch 20 and 2.0 on Ch 1 and 40. Should I be concerned with ~2.0 SWR on 1 and 40? Any ideas on how to lower it?
Teraflex mount has been grounded with braided grounding strap via the extra bolt drilled through the tub. Tub ground to bare metal with dremel around bolt/washer holes.
Cheers
The best SWR I am able to achieve with my Astatic PDC7 is 1.2 on Ch 20 and 2.0 on Ch 1 and 40. Should I be concerned with ~2.0 SWR on 1 and 40? Any ideas on how to lower it?
Teraflex mount has been grounded with braided grounding strap via the extra bolt drilled through the tub. Tub ground to bare metal with dremel around bolt/washer holes.
Cheers
Some people have good luck with the Firestik and some don't, I have witnessed the tail light mount torn off while on the trail and consider upgrading the coax to RG-8U. Recommend you borrow a stainless 3' whip, move the antenna mount to the tire carrier area and then retest that antenna SWR...
I would bet you would end up with an SWR of <1.5 across the channels.
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