National "Clean your antenna day".

one-eyed Jack

Manufacturer
Joined
Apr 12, 2006
Messages
15,529
Likes
31,914
Location
Eastern Mass and southern NH
Feedback: 4 / 0 / 0
It was yesterday in case you missed it. One of my 2M only antennas on the roof is a Diamond F23a 3 element co-linear vertical. It's 15 ft long (high). Thin copper rods in fiberglass tubes joined together. Three radials. I was having some issues with it and called Diamond. The tech told me that the exterior of the tubes need to be kept clean. Didn't say why, but told me that the model discontinued. I took it down and cleaned it. Will do the same each Oct 20. Sounds stupid, but a true story. Jack W1FKG.
 
>>The tech told me that the exterior of the tubes need to be kept clean<<

Well, mine's atop a 40' tower, so that ain't gonna happen! ;)
 
Hmm....Phelps Dodge StationMaster antennas and many other brands are built the same way, copper inside fiberglass and if properly supported when mounted, they last for decades. Cleanliness has little to do with it unless it's covered in a thick layer of green algae.

The problem that most fiberglass antennas have is poorly soldered joints on the actual antenna inside the fiberglass tube housing and insufficient internal supports to stop the guts from moving around. They succumb to vibration from winds over time and become staticy and intermittent.
 
I cleaned my antenna this morning, with the wife's help!!
giphy.gif
 
Hmm....Phelps Dodge StationMaster antennas and many other brands are built the same way, copper inside fiberglass and if properly supported when mounted, they last for decades. Cleanliness has little to do with it unless it's covered in a thick layer of green algae.

The problem that most fiberglass antennas have is poorly soldered joints on the actual antenna inside the fiberglass tube housing and insufficient internal supports to stop the guts from moving around. They succumb to vibration from winds over time and become staticy and intermittent.
I took the Diamond apart. The elements are copper rods connected and centered with brass blocks and set screws. all very tight and all looks like new. The fiberglass tubes were not that dirty. The radials are bolted on tight. The issue is that it is directional. Get into repeaters solid in a 180 deg. arc to the east but not to the west. Have had other vertical antennas in the same location with no directional issue. New coax and SWR is 1:1 at 146.0 as advertised. Jack.
 
I took the Diamond apart. The elements are copper rods connected and centered with brass blocks and set screws. all very tight and all looks like new. The fiberglass tubes were not that dirty. The radials are bolted on tight. The issue is that it is directional. Get into repeaters solid in a 180 deg. arc to the east but not to the west. Have had other vertical antennas in the same location with no directional issue. New coax and SWR is 1:1 at 146.0 as advertised. Jack.
Have you walked the area with a field strength meter to confirm signal strength and or directionality?

Isotropic verticals radiate equally in all directions, I find it hard to believe that it would exhibit any directionality without just by mere chance coupling to other antennas throwing the pattern askew.

If your antenna is isolated and in the clear, the directionality thing is impossible.

Have you tried increased power to hit the repeaters in the opposite arc?
 
There's no polar (H-plane) plot of the F-23,
but be very very sure that the electrical connection of all three radials are equally clean.

If one of the counterpoises was making crappy contact,
maybe it would skew the pattern.

Also, if the mast beneath the antenna is stood-off from
(say) metal straps around a chimney, perhaps the straps
would mess up the pattern.

Just speculating...
 
Have you walked the area with a field strength meter to confirm signal strength and or directionality?

Isotropic verticals radiate equally in all directions, I find it hard to believe that it would exhibit any directionality without just by mere chance coupling to other antennas throwing the pattern askew.

If your antenna is isolated and in the clear, the directionality thing is impossible.

Have you tried increased power to hit the repeaters in the opposite arc?
Uzi, you may have hit the nail on the head. I can do 5-75 watts with the radio. Tried all that. BUT! I also have a 10 element yagi on the roof close by and at the same elevation which I can rotate. That may well be it. Back to the dwg board. The previous vertical that worked OK was only a 5/8 and may have "snuck" under the beam. Thanks, Jack.
 
So many things I want to say, I dont want to ruin this thread in case that is actually a thing and you are serious
Chris, please say away. I've been a ham for 53 years and have built antennas, rotors and other home-brewed stuff. See Uzi's post #9. This one just has (maybe had) me stumped. Jack W1FKG.
 
Back
Top Bottom