70foot mast VS 27foot short vert

[flintstone mop]

I might be thinking in the future for a replacement for my shortened MA160V, Cushcraft. It's a 27 foot high top loaded ant. and works quite well. I get very gud sig reports using 250W AM. I am located in Western Pa. and these reports are coming from Vermont/Rhode Island/Maine
Would I see any improvement by constructing a 70 foot mast, insulated from ground and the usual tuning network on the ground, w/ the usual 40-50 ground radials.
Would a capacity hat make any difference? OR because of the increase in height, not needed???

I'll wait for the upcoming radio season and make some A-B tests with Don, K4KYV and others who are "further out" with  my short vert and the inverted Vee.

I know Don is heard quite well with his true radio station type vert ant. There are occasional QSO's into Colo and AZ.
Before my vert, the QSO's Don would have with these folks were un-readable for me. This season will be more concentration on the short vert. I need to have a system at the ant to "move" the freq over the entire 160 band.

Thanks
Fred

[W3RSW]

Not including the radiation resistance loss, most of the DX stuff is a function of the radiation angle, the lower the better for DX. You can improve the existing system by adding more radials of the proper length.  Sounds like you already have a lot of radials.

The radiation resistance of a 27 ft. top capacity hat loaded vertical isn't appreciably much less than a 70 ft. vertical without a hat as far as distant receivers go if you can keep the radiation angle down. Haven't done the calcs., but I bet it isn't an S-unit.  Your already farily far below performance of a full 1/4 wave vertical with infinitely conductive ground plane. 

So you should look at some sort of hat if it's going to be mono-band., say at least four wires off the top tied out as far as you can get them to approach a right angle.  Otherwise I don't think you'll see much improvement.

Makes us wonder how mobile antennae ever work.    But they do, and surprisingly sometimes only 2 or 3 S-units below the house rig.  160 though is another matter.

Compromises, compromises... just like everything else in life

[WQ9E]

Fred,

Given the amount of time it takes to put in a good vertical system for 160 I would strongly suggest you pick up a copy of ON4UN's book "Low-Band DXing" which has a lot of details, tests, and analysis various configurations.  In it you will find some excellent information on various configurations, matching networks, and ground systems.  It is about the size of a late 1970's ARRL handbook and the technical content is on par with the older (and in my view better) league publications of the past.

Although I know your interest isn't primarily DX-ing this book really is a very valuable resource for anyone interested in serious antenna systems (both transmit and low noise receive) for the lower bands.

Rodger WQ9E

[N3DRB The Derb]

Phred,

consider adding a 6 to 10ft spiderweb  cap top hat on your current system. It will broaden out the swr a bit an have some other minor good effects. I dont believe an increase to 70 ft would really net you that much a gain.  With your radial system, you have most of the problem licked. They are full sized radials, right? Thats very important. Some folk think he ant is only x long, therefore the radials only need to be y long. Nope, full 1/4 wave.

[WU2D]

Fred,

Got woods?

Do you have an RF Ammeter? I have been using an RF ammeter at the base of verticals no matter the band to try to increase the amount of current getting into the radiator. Throw away your SWR meter. It pays off.

You can literally see what adding radials or changing radials or adding loading, a capacity hat or ground rods does.

The other thing that some of us have switched to is elevated radials. The general concensus is that 4 elevated radials can outperform all but the serious buried systems. I put them in the woods at 10 feet so they do not take my head off!

73's and good luck!

Mike WU2D 

[N3DRB The Derb]

erg. stop saying how useful rf ammeters are. next hamfester instead of buyin them all daY long for 50 centavos hey'll be 20 bucks. 

[WU2D]

You are right Derb,

If fact meters in general are the last big grab - ain't making any more of those bakelite beauties!

Mike

[flintstone mop]

OK OM's FB
We're visitng some friends this weekend in sunny HOT Flint Mich.
I'm breathing easier on not having to deal with a 70 foot mast. Rohn makes the H-70 for under $200 and about the same price for shipping. The deer can get tangled up in the guy wires and bring the whole thing down in a second.
Very good info on my exisitng vert. DERB, There is a capacity hat on the MA160V. Should I make them longer(?) Would longer cause tuning issues in windy WX, and when the ice cometh, another problem?
I'm building a remote tuning network to be able to use this ant on the entire 160M band. Got a 1000 feet of #20G stranded, 2 cond W/gnd and shield to run to the shack. The vac variable is ready now ( neat 12VDC car-door window motor $9.95 e-Bay) and I bought a variable, motorized inductor from Gary, INR (28vdc motor)and will mount all of this in a 17 inch square cast iron box for shielding and weatherization.

Elevated Radial.......Thanks Mike
I have always thought of the elevated radials. That would stop this madness of sod staples and replacement from mowing expeditions. I'll have to look my situation over and study the antenna books I have. Oh Yes ON4UN is valuable. I do not think there are enough trees around to support a quater wave's worth of radial wire. The thought is inviting because there would be less radials. I'll have to sit and stare at the antenna site with some red wine and 'smoke it over'. There might be a solution. There's still time 'till the bad wx arrives. Here in Western Pa, the middle of OCT gets wet and uncomfortable with the damp cold stuff.

I do have a couple of RF ammeters from the open-ladder days and that really makes good sense, and the final proof, that I'm either moving forward or backward with the antenna. More radials are better............right? The MFJ thing gets me on the air, but doesnt' tell me about radiating RF into the ether.

Thanks guys, I'll check back prolly at work, Tuesday. Monday will be shot driving back home and attending a small 'back-to-school party"

Phred

[N3DRB The Derb]

f fact meters in general are the last big grab

yes they are. I still wish I had my collection of 1920 era 4" and 5" westons. I had 15 of em or so at one time. Never paid more than 3 bucks for one of em. I would watch the munky swing, somewhat slowly, but still highly entertaining. 

[ka2zni]

. I am located in Western Pa.

So am I fred, Not sure where your at BUT maybe sometime we'll have the privilege of working you.

73's,
Kevin
KA2ZNI

[flintstone mop]

Kevin,
I'm in New Castle Pa.
I can't find your call in QRZ?

Fred

[Ralph W3GL]

Fred,

It's listed okay in the FCC database...That's what counts. Qrz isn't official, dontshaknow!l

[Steve - WB3HUZ]

Assuming both are as efficient as they can be, the taller antenna will yield a wider bandwidth.

I might be thinking in the future for a replacement for my shortened MA160V, Cushcraft. It's a 27 foot high top loaded ant. and works quite well. I get very gud sig reports using 250W AM. I am located in Western Pa. and these reports are coming from Vermont/Rhode Island/Maine
Would I see any improvement by constructing a 70 foot mast, insulated from ground and the usual tuning network on the ground, w/ the usual 40-50 ground radials.
Would a capacity hat make any difference? OR because of the increase in height, not needed???

I'll wait for the upcoming radio season and make some A-B tests with Don, K4KYV and others who are "further out" with  my short vert and the inverted Vee.

I know Don is heard quite well with his true radio station type vert ant. There are occasional QSO's into Colo and AZ.
Before my vert, the QSO's Don would have with these folks were un-readable for me. This season will be more concentration on the short vert. I need to have a system at the ant to "move" the freq over the entire 160 band.

Thanks
Fred