Tarheel Locations - Experiences/Ideas?

[N4MU Papi]

I had placed this in another category...forgot this one...sorry.

Here’s a question with no cut and dried answer I know but I sure would like your best guess on the results.

:2cents:Picture a Tarheel 100 sitting in the center of an 8X8 foot metal storage shed. All metal…roof too (flat roof). The antenna base would therefore be about 8 feet off the ground just over the metal roof. What are my chances of it loading? Any improvement using a radial kit (from the antenna base and draped over the shed, then down the sides and then out along the ground surrounding the shed? Would a capacitance hat improvement the loading in this situation? BTW, I run 500 watts.

I know this is weird but I’m getting into a situation where it may be the only possibility. I may also be able to just plop the antenna in the ground a few feet away from the shed and use conventional radial kit but if I can raise the base to the shed roof it would physically be better. (And hidden better)

Just wondering if anyone has ever heard or seen of anything similar. Thanks!

[N3LYT]

Tarheel says to ground mount it with radials. However I think it will work just fine on your roof. They will tune pretty much where ever you put it the problem comes when you try to contact some one! The bottom line cars/truck are not real good ground planes any way. I have a HS mounted at the rear of my camper up maybe 7-8' it's roof is aluminum and frankly it works great. A cap hat may help the lower bands all though mine works fine on 80 meters.

[NN5I]

It's my understanding that most Tarheels are in North Carolina.

[N3LYT]

It's my understanding that most Tarheels are in North Carolina.
Well some have made it to Maine but that was after careful consideration.

[ke0me]

After having the lil tarheel II in a box in a corner for a month, finally got around to starting to assemble it.

For now, I just set it up here inside the apartment, not to actually work anything, just to assemble it and test.

I also purchased an AA-30 antenna analyzer ( Made in the Ukraine). What a nice piece of equipment.

All i do is run a SWR scan and see how many turns on the antenna motor gives me what resonant frequency (approx, Im indoor and too many metal objects around). I can calibrate it accurately later when outside, I was just checking function and wiring.

So, in another month I should be able to figure out the mount on the trailer, and I'll be ready to get on the road at the end of May.

PS- 66 degrees today, another snow storm tomorrow night.

[NN5I]

... purchased an AA-30 antenna analyzer (Made in the Ukraine). What a nice piece of equipment.

Yes -- the RigExpert stuff is the best. I have an AA-230 Pro that I bought about five years ago, and can't imagine being without it. Nothing else comes close.


PS- 66 degrees today, another snow storm tomorrow night.

Sunny in Tallahassee today, about 75 degrees, light variable wind. But it poured rain for four previous days runnin' -- as we say here.

[N3LYT]

Bird AT 100 and AT 400 nice graphic analyzers.

[N3LYT]

After having the lil tarheel II in a box in a corner for a month, finally got around to starting to assemble it.

For now, I just set it up here inside the apartment, not to actually work anything, just to assemble it and test.

I also purchased an AA-30 antenna analyzer ( Made in the Ukraine). What a nice piece of equipment.

All i do is run a SWR scan and see how many turns on the antenna motor gives me what resonant frequency (approx, Im indoor and too many metal objects around). I can calibrate it accurately later when outside, I was just checking function and wiring.

So, in another month I should be able to figure out the mount on the trailer, and I'll be ready to get on the road at the end of May.

PS- 66 degrees today, another snow storm tomorrow night.

I can tell you the motors drift after power is lost they will be close but it usually takes a tweak to get the SWR spot on. I use a turns counter controller and usually have to tweak it when changing bands. It takes 20 turns to advance one inch so a couple of unregistered turns will effect the SWR.

[ke0me]

I was doing a test inside the apartment with minimal ground and I noted how much difference there is as you tune down in frequency. I do have a frequency counter so that really helps.

for example,
10 meters 4 turns from park
15 12
20 28
30 40
40 80
80 240

I know this is not accurate compared to when I get outside, but it is interesting to me to see how much additional turns are required (i.e. more loading coil turns) as you go down in frequency.

Also, with the ant analyzer, I can change the range and frequency of the swr scan with +/- keys, and don't have to reenter frequency and range. Really easy to use.

Needless to say, the lowest swr on each band was nowhere near a 50 ohm non-reactive load. The best was 40 meters, got a 1.7 SWR, Z= 84 - j8.6

Cant wait to get outside and get it into open airspace!!

[ke0me]

Finally a nice day and no major chores to do.


Took the Tarheel outside (about 8 feet off the ground), u-bolted the pipe mount to a wood balcony. Ran about 8 ft of ground braid from the ground lug of the mount to the heating system water pipe, and finally, added about 16 feet of wire to the ground lug. The 16 ft wire does not touch the ground wire and is sort of an "L" shape.

Using the antenna analyzer, great results. I only checked 40 and 20 meters due to time. lowest SWR were under 1.5:1 on both bands.

Inside, I could actually hear stations! Guess it helps it is also SSB Sprint contest weekend.

Main reason I did the test was to get a better feel for how many turns are needed for a specific band, and effect of close by metal objects, of which there are many. Tuning on the higher bands is very tricky, like maybe one turn moves the center freq 250 KHz (or is it kHz).

So, now I'm looking forward to a nice warm weekend when I get out and design the mount for the trailer and figure out how to run counterpoise and/or radial wires on the trailer.

[NN5I]

one turn moves the center freq 250 KHz (or is it kHz).

It's KHz. The international convention is that you use an upper-case letter for multipliers that are greater than one, and lower-case for multipliers smaller than one. This helps distinguish, for example, between the abbreviations M for the Mega prefix (multiply by a million, greater than one) and m for the milli prefix (multiply by 1/1000, less than one). Similarly P for Peta (a quadrillion) and p for pico (a trillionth); D for Deka (10) and d for deci (1/10). There are other such pairs (Yotta and yocto, Zetta and zepto), but we don't see them much in Amateur Radio.

For prefixes like Kilo this is not universally followed (no smaller-than-one prefix starts with k), and some authorities say the convention doesn't actually exist and the short form for kilo is k. Pooh.

[ke0me]

Carl,

I knew I could count on you for the correct info!

I had enough trouble converting from Cycles to Hertz a few years ago.

Thanks.

[NN5I]

Carl, I knew I could count on you for the correct info!

You do understand that a careful reading of my post leads to the (correct) conclusion that I'm uncertain, right?

[N3LYT]

Tarheel grounding kit http://www.hamradio.com/detail.cfm?pid=H0-010496

[N4MU Papi]

Hi Dick. I will be very interested in hearing about your tests with the TH antenna. Was it a model 100 or what model?
I have had a 100 mounted on the ladder of my fiver since we've been in the "temporary" park (last June) we're in and to tell you the truth it has worked great. Rarely is there a station I hear that hasn't come back to me. I'm running about 400-500 watts with an ALS-600 to the TH and I know that helps but I am genuinely surprised at the performance. I have made no attempt at grounding or radials, etc. It just is mounted to the top of the ladder.
I will be retiring in a month (YEA!) then it's off to the permanent location in a RV resort in FL and I will try the exact same approach there but I also want to test the TH mounted over the top of an 8 foot square metal shed that is located on each lot. Robert at TH said it should work great. I will bond the mount to the shed and see what improvement may be had. I will keep you posted...please do the same with your project. I will appreciate hearing what you may discover.
73, Bill

[N4MU Papi]

Oh BTW Dick. I had the same problem ever since I've misplaced my slide rule.
However, I found out that there is an app for that too.

[NN5I]

I will be retiring in a month (YEA!) then it's off to the permanent location in a RV resort in FL

Where in Florida?

[N4MU Papi]

We will be at Travelers Rest Resort near Dade City. I know...you just want to come by and get that cycles to hertz app don't you?

[NN5I]

We will be at Travelers Rest Resort near Dade City. I know...you just want to come by and get that cycles to hertz app don't you?

Naah. I don't think Hertz rents cycles anyhow.

[ke0me]

Carl,

I don't know how you come up with those lines, hilarious!!!! Keep them coming.

Bill,
I will keep you posted on progress. We are supposed to be back on the road in June, will have update sometime in June probably.
Congrats on your retirement!!

See new post for next technical question that will undoubtedly generate smoke and heat and just perhaps some light! :-)

[NN5I]

Carl, I don't know how you come up with those lines

Borrowing an expression from Ayn Rand's Atlas Shrugged, they just come out of me spontaneously, like vomit out of a drunkard.

[N3LYT]

Hi Dick. I will be very interested in hearing about your tests with the TH antenna. Was it a model 100 or what model?
I have had a 100 mounted on the ladder of my fiver since we've been in the "temporary" park (last June) we're in and to tell you the truth it has worked great. Rarely is there a station I hear that hasn't come back to me. I'm running about 400-500 watts with an ALS-600 to the TH and I know that helps but I am genuinely surprised at the performance. I have made no attempt at grounding or radials, etc. It just is mounted to the top of the ladder.
I will be retiring in a month (YEA!) then it's off to the permanent location in a RV resort in FL and I will try the exact same approach there but I also want to test the TH mounted over the top of an 8 foot square metal shed that is located on each lot. Robert at TH said it should work great. I will bond the mount to the shed and see what improvement may be had. I will keep you posted...please do the same with your project. I will appreciate hearing what you may discover.
73, Bill

Well I guess the amp does help with a QRP signal out of a screw driver antenna and a 100 watts.