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Message |
    
Danusee
Junior Member
Username: Danusee
Post Number: 27
Registered: 10-2004
| | Posted on Sunday, January 15, 2006 - 7:02 pm: | 
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I bought a used A99 last night for $15. I didn't like the flimsy top section so I got a long stainless bolt cut the head off, screwed the into the middle section and clamped 2 sections of aluminum to the bolt. I cut the aluminum section to length to get the lowest swr which was 1.1/2:1 on channel 20. It went to 1.3/4:1 on channel 1 and 40. I haven't tried transmit but receive seems to be very good. It is on my test tower now only 14' to the bottom.
Dan |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1156
Registered: 7-2004
| | Posted on Sunday, January 15, 2006 - 8:33 pm: |
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Those fiberglass swinging tops are alot
stronger than you think. Good Luck with
your replacement metal top piece.
Good deal for $15 |
Danusee
Junior Member
Username: Danusee
Post Number: 28
Registered: 10-2004
| | Posted on Sunday, January 15, 2006 - 9:44 pm: |
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It seems to be a very sweet antenna. Got to try it out tonight. A very good receive and transmit to match. I am going to wait till it rains and see how it does. If it is ok it will probably be going up on top 42' tower.
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Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1029
Registered: 9-2004
| | Posted on Sunday, January 15, 2006 - 10:46 pm: |
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how long did your top section end up being? |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1030
Registered: 9-2004
| | Posted on Sunday, January 15, 2006 - 10:49 pm: |
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danusee, you should check this thread out. you will find it very informative.
it is down this page just a bit. in this section.
just look down.
its called, "top one upgrades and firestick A-99 upgrade"
matt |
Danusee
Junior Member
Username: Danusee
Post Number: 29
Registered: 10-2004
| | Posted on Monday, January 16, 2006 - 7:44 am: |
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Kid, I didn't measure it but I think it was around 2" shorter. The fiberglass section needed the same however, that is because the swr on channel 1 and 40 showed it was just a tad bit long but not much.
I was wondering about the FS99 upgrade but not anymore.
After I put the aluminum tube sections on I got the thought that the steal whip would have been easier. |
Marconi
Advanced Member
Username: Marconi
Post Number: 519
Registered: 11-2001
| | Posted on Monday, January 16, 2006 - 10:29 am: |
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Danusee, you are right the Steel whip would have been easier, but generally they are too long. The original tip in the A99 is about 72" and the SS whips are about 102".
102" will probably work OK because length out there on the end sometimes doesn't make that much difference in some antennas, but you will just have to experiment and may have to cut the steel whip if used. |
Dale
Intermediate Member
Username: Dale
Post Number: 262
Registered: 12-2002
| | Posted on Monday, January 16, 2006 - 4:53 pm: |
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i wonfder if that helped with excessive noise the a99 and imax2k are noted for.the 102inch sswhip should work fine on the imax |
Danusee
Junior Member
Username: Danusee
Post Number: 32
Registered: 10-2004
| | Posted on Tuesday, January 17, 2006 - 7:35 am: |
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Well, with hard rain there was no change in the swr and there was no noise at all. That was at night however. What little time I listened to it during the day the receive seemed very clear. I don't know how the conditions were. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1044
Registered: 9-2004
| | Posted on Tuesday, January 17, 2006 - 5:36 pm: |
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dale, the bad rep. given to the A99 was beacuse a big batch of them were left unsoldered at the connector, thus leading to a bunch of static and noise.
check out Tech833's review of the IMAX. you will see that they have corrected this problem. yes, i am aware that fiberglass antennas "seem" to pick up more noise than aluminum ones, but i cant comment on why.
danusee, are you saying that you had to cut the original fiberglass top section by 2" to get the antenna to tune?
was this after you tuned it with the tuning rings?
the reason im asking, is because i have seen, heard, used, and bought a lot of these antennas, and i have never heard of nor seen one that needed to be cut to tune.
sounds to me like there are other problems with this particular antenna. did you buy it new?
matt |
Danusee
Junior Member
Username: Danusee
Post Number: 33
Registered: 10-2004
| | Posted on Tuesday, January 17, 2006 - 8:05 pm: |
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This is a used A99. The tuning rings went all the way down. It still showed the swr slightly high on 40. So while I was at trying to see what a aluminum top section would do I cut it back slightly.
Anyhow, with it getting dark, 30 degrees outside, 1" of snow on the ground, still snowing blowing sideways I climbed up 40' today and put up the A99 with the aluminum top section.
It is doing very well. I put 7 s unit on a station 20 air miles that has a A99 also. The receive matches the transmit. I am mighty pleased. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1056
Registered: 9-2004
| | Posted on Tuesday, January 17, 2006 - 10:53 pm: |
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ummm, danusee, did you know that lowering the tuning rings lowers the resonant freq. of the antenna, and that with the rings all the way down, it would make sense that the SWR would be higher on 40?
did you at least try turning the rings all the way to the top before cutting the antenna?
i think you should get a 102" fiberglass whip and cut it down to 72" and try the tuning rings again.
matt |
Danusee
Junior Member
Username: Danusee
Post Number: 35
Registered: 10-2004
| | Posted on Wednesday, January 18, 2006 - 8:04 am: |
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Kid, I did try that the full range of the rings. It suprised me it went the way it did. It is doing very good now at 20 miles. At 35 miles it is down but keep in mind it doesn't have a GPK. I will more than likely put one on just to see what happens. |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1170
Registered: 7-2004
| | Posted on Wednesday, January 18, 2006 - 6:57 pm: |
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When all the original parts of the A-99
are used the tuning rings should be about
in the center for ch 20, at least thats what
i found with the (2) A-99's i own.
Don't know what the deal is with Danusee
A-99 if tuning rings needed to be moved way
down.
As long as it makes you happy, i wouldn't worry about it.
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