A99 higher SWR in CB band, but not in 'C' band

[hookedon6]

so if the top section is proper length then WHY would it be doing this?

gee, page 2 ,..... and no one has said the coax is the wrong lenght

 

[mr_fx]

gee, page 2 ,..... and no one has said the coax is the wrong lenght

oh god please don;t say that, I hate when people say that...

unless the coax has become part of the antenna system then coax can only effect SWR if something is wrong, and then that would be high SWR on ALL channels

in general is trimming your coax back makes a difference then it just means you had a faulty connector or you soldered the new one on better than the old one

 

[mr_fx]

top section measures 70" but should measure 72"

 

[RatsoW8]

top section measures 70" but should measure 72"

To really know what's going on you need to put an antenna analyzer on it to check the 2:1 swr bandwidth. If it's just tuning a little low, cut 1/2" at a time from the top until you get centered on channel 20 if the CB band is where you what to operate. That A-99 isnl't that complicated an antenna. Cheaply made yes...complicated no. Not all of them tune perectly.

 

[mr_fx]

well I took the antenna down off the roof and test mounted it about 7 foot above the deck in the back of my neighbor's house... also used about 18 ft of RG58 instead of 65ft of RG8

SWRs dropped in the CB band to around 1.2-1.0 I can;t leave the antenna mounted to the side of my neighbor's deck... lol so ideas?

could it I can't see it being coax related... but...

 

[Robb]

Either the coax has issues - or where it was mounted.
Probably where it was mounted - IMO . . .

 

[mr_fx]

Either the coax has issues - or where it was mounted.
Probably where it was mounted - IMO . . .

what about a ground wire issue... I was grounded when I was on the roof... not grounded on the floor

 

[RatsoW8]

what about a ground wire issue... I was grounded when I was on the roof... not grounded on the floor

LOL..you completely changed the location of the antenna, the mounting height and the coax type an length so I would expect the swr to change a little.

The swr readings you gave intially are pretty darn good to begin with except above channel 40. What are you expecting from the antenna? Just curiois.

Robb was right on target with his first reply that the antenna is a little too long. SWR or 1.05:1 below channel 1 and 2.2:1 above channel 40 means the antenna is a little long. Shorten it a little. I think it's that simple. Did I miss something along the way??? If I did I'll shut my pie hole

 

[Needle Bender]

If you take it down check the tip length. It should be 72" long if it is stock, and I think the A99 has Antron, Holland, Ohio printed on the plastic cover on top. That might tell you if the length has been changed.

You might also compare you radio bands and see if they all produce about the same RF output using a good dummy load. The SWR may show about the same with such a setup, but the watts could be different. If so, the radio is not tuned right, but if it is not much then, "don't worry about it."

unless it has a 6 foot (72") wound 1/4 wave like a francis replacing the original top for a lower band like 12 or 15 meters but thats suposed to help performance according to other forum posts ive read.
i think you set the rings higher to tune it for higher frequencies right?

 

[Robb]

what about a ground wire issue... I was grounded when I was on the roof... not grounded on the floor

Sooooo . . . Use the same ground wire at the new location and tell us what is happening then.

Never heard of antenna getting a worse SWR and bandwidth problems with proper grounding.

BTW:
Are you using a Ground Plane Kit on this antenna?
If using a steel mast to support it - how long is it?

I run an Imax 2000 w/20 ft of steel mast and no GPK and my bandwidth across 10, 11, and 12m is usable and solid. Needing only to use a tuner slightly just to clean up the SWR - but nothing above 2.0 SWR by any means.

 

[mr_fx]

about 15 ft steel mast

no way to reach the ground over to it

 

[hookedon6]

... mounted it about 7 foot above the deck in the back of my neighbor's house... also used about 18 ft of RG58 instead of 65ft of RG8

SWRs dropped in the CB band to around 1.2-1.0 ...
could it I can't see it being coax related... but...

I'M not gonna say I told ya

now put a dummy load on your 65 feet of RG8 and see what you get

 

[mr_fx]

well I finally said the hell with it and climbed my butt up on the roof with a radio and power supply and an 18ft chunk of RG58u

SWR are flat...

so now I need to decide if I want to solder new ends on the RG8u or just order new cable... which will take forever

 

[mr_fx]

all the jumpers I made have been fine... the SWR's go worse as it got colder outside... SO maybe the issue is a bad solder joint on one of the connectors...

I could just hack them both off and reroute the coax... the way I want to reroute it would shave around 20-25 feet off the length

 

[Robb]

Maybe a water ingress problem with an old piece of coax?

If it is an old piece, I would cut off the length from the end that was outside/exposed to the elements.

Did you test the coax with a dummy load on the other end?