VERTICAL GROUND SCREEN

[flintstone mop]

Here are some pics of the re-born one more time vertical.
The raised radials were good but had to come down to protect me and my neighbor when we mow. So now using vinyl covered welded fence. #16 steel and tack soldered using silver solder in many places to the copper strap. I can move and pull the joints and nothing breaks loose. The fencing was 36" wide and 50 feet long. I installed five rolls, and will fill in more later.
The grey paint protects where the fencing was burned from the blow torch and the tack soldering. I wanted to get 1"X2" squares but that would double the cost of the fencing. So I settled for 2"X3" squares. I also re-connected the 70 radials. They are, whatever is left after two years, 120 feet long.
The vertical now has an impedance of 70 ohms...........not the real vertical impedance of 36 ohms. And no Xs on the MFJ meter..........I'm guessing it's s series reactance. I have noticed with several antennas that if the Xs gets into double digits the antenna performs poorly. Single digits and or 0 is getting wonderful.
I need to shorten the stinger. The capacitor runs out at 1000 PF right where I need to resonate at 1880 or so. With minimum capacitor, prolly around 10pf the antenna loves 1836. The antenna is the MA160V. 27 foot high top loaded and top hat.

[flintstone mop]

OK pictures

[flintstone mop]

AND the tuner

[KM1H]

Thats a serious tuner Fred and I like that ground screen at the base where it does the most good.
Are you going to add some radials to the far end of the screens?

Carl

[KA8WTK]

Just ley the grass grow through the screen and cut it longer than usual for a while. All that screen will dissapear!
Nice job Fred.

[KB2WIG]

I hope that is painted  Saint James Gray.  You'd be a piker if its a 'cheep color' paint.


klc

[K5UJ]

Fred I recall before there was some kind of problem with the feedpoint tuner, maybe the inductor frying or something.  Looks like you got serious 

It shouldn't dissipate much heat.

Rob

[flintstone mop]

Carl, I reconnected the existing radials from the first install. There were close to 60 and 120 feet long.
And Rob, there were many bad memories for the coil. For some reason I always come back to the overkill design. The motor for the vac variable was from a BC1H power control. The motor would turn a huge wire wound pot.
There is a magical combination of coil taps and the vac variable that could allow me almost the entire 160M band. But I'll just get it to be happy around 1885. THis Cushcraft antenna is a little different design from the Unihat vertical I had in the late 90's. The Unihat CTSVR was a very effective antenna for top band. The ARRL field tested the Unihat with several other verticals. It was worth the extra money.
Fred

[K5UJ]

I almost bought the original UniHat which was made by some ham in I think, Dallas, but it seemed kind of expensive and I went with an inverted L instead.   I look forward to working you this fall on 1880 or 1885 Fred.  I normally take a break from 160 in the summer time.

Rob

[flintstone mop]

I almost bought the original UniHat which was made by some ham in I think, Dallas, but it seemed kind of expensive and I went with an inverted L instead.   I look forward to working you this fall on 1880 or 1885 Fred.  I normally take a break from 160 in the summer time.

Rob

Rob the price took my wallet for a loop but well worth it. A major cost was the dacron rope. THe dam thing is guyed at three places on the mast and 4 guy points on the ground. Nothing would take that tower down.
I used that thing for all of my 160M in the late 90's. DX and hearing the left coast was not too good. But cudda been my little radial system too.
Great small lot antenna. I am in contact with Ed. N5UG. To try to see if he is selling any of these. A Texas Ham, who designed this antenna and even got FCC approval for broadcast.
I'd like to get another one cuz with just the variable cap and a sweet spot setting of the coil tap I could run from 1830 to 1890. This Cushcraft antenna is not a happy camper.
I think the top loading coil and the tiny capacity hat makes it a completely different antenna.

[K5UJ]

I remember the original unihat had a gigantic top hat.  I can't remember how tall it was but the big top hat kind of turned me off of it because I didn't know how well it would hold up.