[TenTec] Antenna follow up- asked for help in January- need more help.....

[Rick - NJ0IP / DJ0IP]

Tom, 

You should be able to tune the entire band, no problem.
You may have to add (or cut off) another 2 ft. of feedline.

Tuning can sometimes be very critical.
I put bigger knobs on my 974 matchbox so that I had a better "fine feeling"
when tuning.

I believe if you change the inductance, either one notch up or down, and
fine tune, you will probably be able to get a low SWR over the entire band,
as is, without any further pruning.  If not, prune a bit more.

73
Rick

-----Original Message-----
From: tentec-bounces at contesting.com [mailto:tentec-bounces at contesting.com]
On Behalf Of tom stewart
Sent: Monday, February 14, 2011 11:22 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Antenna follow up- asked for help in January- need
more help.....

This did in fact work well for me tonight. The bands are not great tonight
so I did not make any contacts but at least I can tune up on 7,10,14 and
18mhz. It is a little touchy on 40 as it dips at 7.5 but it is OK at 7.025.
The resistance is around 600 and the reactance is near zero. In fact all
those bands have a similiar result- high resistance and low reactance- that
is OK I think. It is resonant on 18.068 which is cool. I have made many DX
contacts on 18

Thanks for your help- Tom N7ESE

..On Mon, Feb 14, 2011 at 3:40 AM, Rick - NJ0IP / DJ0IP
<Rick at dj0ip.de>wrote:

> Tom,
>
> Here is a probable fix for 40m.
>
> If you have any of the commercial 450 ohm ladderline, use it and add 13
ft.
> of line to the antenna.
> I assume you can run it inside your shack, which is why I say to use
> commercial stuff (easier to work with and zigzag back and forth than the
> home made stuff).
>
> If you don't have commercial ladderline, then add about 15 (or 14 ft.) of
> your homebrew openwire to the feedline.
>
> The trick is to add an electrical 1/8 wavelength.
> I don't know the velocity factor of your home brew line, that's why I
can't
> say the exact length but it will be about 14 or 15 ft, maybe even 16 ft.
>
> I'm pretty sure that will fix 40m, and probably 30m as well.
>
> MOST LIKELY, THE ONLY PROBLEM YOU ARE HAVING IS THAT YOU HAPPENED TO HIT A
> VERY UNPRACTIVAL TOTAL LENGTH OF ANTENNA PLUS FEEDLINE!
>
> I use the same antenna with the same matchbox (I have the MFJ-974B) and it
> produces a very good match on ALL bands, from 80 thru 10, but I have a
> longer feedline, whose length I have not measured.  It runs exactly from
> the
> antenna to the shack, and I got lucky!
>
> 73
> Rick
>
>
>
>
>
> -----Original Message-----
> From: tentec-bounces at contesting.com [mailto:tentec-bounces at contesting.com]
> On Behalf Of tom stewart
> Sent: Sunday, February 13, 2011 7:17 PM
> To: TenTec at contesting.com
> Subject: [TenTec] Antenna follow up- asked for help in January- need more
> help.....
>
>  OK,
>
> Many came to my aid when I asked for suggestions. I made some choices and
> built an antenna. I tried hard to maintain spacing and avoid metal by at
> least a foot. It did not come out well so I need help. Here are the
details
> if anyone has some suggestions I would be grateful-again.
>
> 1. Purchase "Ladder Snap" spreaders to build 600 ohm feeder.
>
> 2. Purchased plenty of 14 gauge THHN wire.
>
> 3. Because of room constraints, the legs of my inverted Vee are 31 feet.
> Center is 35 feet high and the legs end at about twenty feet.
>
> 4. Legs to feeder is continuous- feeder is 45 feet from center  and
> terminated by grounded shield coax through window pane(vinyl).
>
> 5. Tuner is for now an MFJ balanced- model 974-I think.
>
> 6. reactance is high on all bands. It will only tune up on 14MHZ.  tuner
> arcs if I persist at 7mhz
>
> 7. readings with antenna analyzer are as follows:
>
> Readings are at the bottom of the bands beacause I operate CW only.
>
> 7.020mhz       r57       x158      swr 10.0
>
> 10.110mhz     r168     x 135     swr 6.0
>
> 14.020           r21        x58       swr 7.5
>
> 18.075          r20        x70        swr9.1
>
> Thanks in advance- I know it is difficult to say with this limited
> information but I am at my wits end- about 10 hours into this
>
>
> Tom N7ESE
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"No matter how fast you miss, you still lose."
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