A99, HIgh SWR, and just lack luster performance and how I fixed it...

[mr_fx]

Well my A-99 was showing it's age when I bought it...

the fiberglass was cracked, but hey it was only $20 and it was about a 1/4 mile from my house...

to fix the fiber glass I simply used for polyurethane floor sealer

however SWRs never really impressed me... 1.2 on channel 1 and 2ish on 40

however it was FLAT a band lower than CB

well I found that the coax where falling apart... not a good thing

SO I replaced the coax with some new RG8 mini

SWRs dropped to around 1.7 at the worse... still not going to cut it...


THEN I took some RG8 Mini and made a choke that was 5 turns @ 4.25"

this got me the following SWR readings:

1 - 1.325
40 - 1.125
-40 - 1.625
-80 - 1.95
-120 - 2.25
+40 - 1.7
+80 - 2.75

still nothing to write home about...

now I got rid of the ground wire... and isolated the antenna from he mast, using a 1.5" diameter dowel

then I took some scrap Aluminum tubing, L brackets, misc fasteners and hose clamps...

with this I built a simple yet effective ground plane kit..

now with out even telling the locals they asked me what I did differently

it even sounds better...

most importantly it has GREAT SWRs:
26MHz - 2.3
26.25 - 2.25
26.5 - 1.8
26.75 - 1.35
26.95 - 1.175
27.205 - 1.00
27.405 - 1.00
27.50 - 1.05
27.75 - 1.25
27.99 - 1.60

 

[BOOTY MONSTER]

freecell use to say that was the best way to use them and the imax 2000 . wish he was still around to post his opinion of the gainmaster .


http://www.worldwidedx.com/cb-anten...endfed-antennas-their-support-structures.html

 

[walterb]

A99/ SWR

mr_FX
I like your style, you took an A99 with a blown matching cap in it an made the antenna work again, your my kind of guy BRAVO an had some FUN doing it!
KB6HRT

 

[walterb]

BM,
This is something I do, use the vent pipes on my house which are PVC have when putting a A99 or a IMAX up and make a choke out of coax excess coax I may have, have had good results do so!..........KB6HRT

 

[BOOTY MONSTER]

there ya go

 

[wavrider]

Glad you got it working for you. Half the fun of the hobby is making something work, the other half is making the contacts.

 

[HomerBB]

I thought the other half is making folks mad on forums . . .

 

[Marconi]

mr_FX
I like your style, you took an A99 with a blown matching cap in it an made the antenna work again, your my kind of guy BRAVO an had some FUN doing it!
KB6HRT

Walter, where did you hear about this blown matching cap? Mr_FX didn't say this above in his list of fixes.

Plus an A99 has a 2.25" x 3/4" piece solid brass thick walled tubing used as a capacitor like noted below, and I doubt that will blow up very easily. I guess the PV insulators in the ends of this brass could melt maybe. He did say he repaired the FG with polyurethane however, but that alone will not likely ill-affect the antenna performance unless it won't stand up.

 

[mr_fx]

BamBamm, it would work on the Proton99 which is just a knock off A99, at least that is what I have heard