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Homer's Qv4k

HomerBB said:
There are changes that were made to the Qv4k that has resulted in movement in the SWR that I find favorable. Primarily, the changes were made to the 4 radials - length and diameter of the elements - and to the gamma match. Also, the length was reset to 29' 1".

The above posted SWR was where I landed with those changes while the antenna was mounted on the temp testing pole very near the house and close to the ground, if I recall around 14' from the earth.

This is a view of the changed radials: 90" from where they bend away from the center vertical to the tip ends, and 3/4" diameter.

4868.jpg


Closer up while the antenna is laying on its side you can see the close-ups of the changes to the Gamma Matching setup. The dogbone is now set at 36" up from the feedpoint of the antenna, the gamma tube is now 17" x 3/4" OD, the rod is 36" x 3/8" and pulled out from the tube 25.5" which brings the tap point around 19". Additionally, between the rod and the tube there is a nearly snug fitting dielectric tubing running the entire inner length of the tube.

4884.jpg
4883.jpg


Here is a snapshot of the Qv4k sitting above the Yagi on the tip-over mast just as the sun is setting.

4887.jpg


After the antenna went up higher into the air, sitting just above the yagi about a foot, the SWR curve shifted upward some.

Here it is currently from the 2.0:1 reading upward:

26.515 -------------------------- 2.0:1
26.965 -------------------------- 1.2:1
27.205 -------------------------- 1.0:1
27.405 -------------------------- 1.0:1
27.855 -------------------------- 1.0:1
28.305 -------------------------- 1.2:1
28.755 -------------------------- 1.2:1

I do not know where the SWR goes upward from there as I ran out of frequencies on the DX88HL.
Click to expand...

Hi Homer, I've been following your progress. I'm impressed. You xcan stick with a project until it works, I wish I could teach my stubburn son to do that. dDo you think you could post your end mesurements? and did you check it for reactence or only for swrs?
Nice job.
 
looks good homer , and cleaner too . have you had a chance to get a feel for how its performing yet ? now i know why the pex worked for your 3/8 rod and gamma tube but not mine . i thought you had 1/2 inch inside diameter tube for your gamma , but the 3/4 is probably 5/8 inside diameter ;) . be sure to let us know how shes talkin' and hearing .
 
I figure it's just my view point, and maybe reflections from the metal in the picture, but... those 'radials' aren't wrapped in foil, are they??
- 'Doc
 
Meglotron said:
Hi Homer, I've been following your progress. I'm impressed. You xcan stick with a project until it works, I wish I could teach my stubburn son to do that. dDo you think you could post your end mesurements? and did you check it for reactence or only for swrs?
Nice job.
Click to expand...

I borrowed a MFJ-259B analyzer, but it was way out of calibration and useless, so so far only SWR. Maybe later if he can get his analyzer tuned up.
 
BOOTY MONSTER said:
looks good homer , and cleaner too . have you had a chance to get a feel for how its performing yet ? now i know why the pex worked for your 3/8 rod and gamma tube but not mine . i thought you had 1/2 inch inside diameter tube for your gamma , but the 3/4 is probably 5/8 inside diameter ;) . be sure to let us know how shes talkin' and hearing .
Click to expand...

This I'll do. It was too late yesterday to do much and only a little local talking. I did talk to a fellow for a while in Lampe, MO from my place on it. It's a mere 43 mi trip to the northeast of me, but incredibly hilly. It's a 1 1/2 hr road rip that ranges from 59 miles to 68 miles based on which route one takes.

It was encouraging. Of course the first DX contact I made on it after the newest mods, and before I raised it higher was to 399 JJ in Colombia, South America.
 
W5LZ said:
I figure it's just my view point, and maybe reflections from the metal in the picture, but... those 'radials' aren't wrapped in foil, are they??
- 'Doc
Click to expand...

Yes, Doc, your eyes aren't tricking you. These radials are made from a plastic coated garden stake that is a light steel tube internally. There is mechanical contact to the insides, too, but I wanted the whole thing to be aluminum. In due time I will replace the stakes with aluminum tubing, but not until I'm satisfied with my design. Too expensive to play with.

Street view:

4898.jpg
 
Last edited:
The Qv4k has given me several days of radio pleasure.
What I notice about this antenna is its great ears. Close in local is as expected, but what I am finding is the improvement in being able to hear stations beyond 40 miles regularly which has challenged me from my QTH. I had also feared that I would not experience the low TOA expected from this antenna and have to resort exclusively to the Yagi for very long distance DX contacts. I haven't been disappointed with its performance, yet. When the band is open I am talking to Colombia, South America, Hawaii, and Australia on the Qv4k. The 4 element Yagi still demonstrates more gain directionally, but I am able to hear and be heard where I have not been able on an omni from my location. We all know that DX depends on conditions above all else, but when experiencing RX/TX differences with this omni after redoing it to what I did before on it, I have to say that it has been worth my while to get back to it. (y)
 
Robb, it is extremely difficult to accurately assess the cost of this antenna. It was constructed from materials that were parts of previous antennas. I will try to figure it out.

Maybe $60 in the vertical shaft. $23 in the radial basket and loop. $5 worth of screws and a used coax connector. $10 on the Gamma match. so I'd guess around $100 all together. Could be less, but not more.
 
Homer if you can recall, how does you Qv4K compare, RX/TX, to the AstroPlane I think you had up there last.
 
So far, it seems to compare favorably on the side of the Qv4k.
To be sure I will have to use it longer, and I want to pinpoint the location of some distant non-DX stations I am hearing I do not recognize from before.
 
hey homer how high is the feed-point of the antenna from the ground now ?
how high and far is the peak of the roof from the feed-point ?
i think you mentioned earlier , but im feeling lazy .

im glad to see you're able to change the antenna to tune to your bands and still get the great results you're getting !!
 
BOOTY MONSTER said:
hey homer how high is the feed-point of the antenna from the ground now ?
how high and far is the peak of the roof from the feed-point ?
i think you mentioned earlier , but im feeling lazy .

im glad to see you're able to change the antenna to tune to your bands and still get the great results you're getting !!
Click to expand...

The current location has the feedpoint at 32' above ground. The tower stands away from the house so it is not near the roof, however, the maximum height of my roof is the ridge and it is 17' above the ground. The distance of the roof ridge from the feedpoint is 50' across the ground from the bottom of the mast.

I am considering moving the feedpoint another 4 feet up to the 36' mark.
 

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