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Leader 2M antenna tuner

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Jim

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Mar 18, 2004, 7:38:17 PM3/18/04
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Hi: Need alignment instructions for a Leader Instruments LAC-897 2M. Antenna
Coupler form the 1970's(?) . Have an owners manual, but no alignment
instructions,
Thanks,

Jim
WA8SDF

Dale Parfitt

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Mar 18, 2004, 10:57:42 PM3/18/04
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"Jim" <bar...@eos.net> wrote in message
news:BC7FAB2A.326B7%bar...@eos.net...
No clue there except that an antenna tuner for 2M is usually a very poor
idea as line loss from elevated VSWR can make the system very inefficient,
even though the rig is matched to the line.

Dale W4OP


Tuuk

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Mar 19, 2004, 8:00:22 AM3/19/04
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Hi Dale
Are there any websites or information available to explain more detailed
about using antenna tuners for 2m ? I use two, one for 2m and one for
156megs frequently.

The antenna tuner does bring the reflected power down to almost 0 to the
radio and improves communications both receive and transmit. Could there be
a hidden damage or danger?

Thanks

"Dale Parfitt" <p...@parelectronics.com> wrote in message
news:Wcu6c.63294$rW6....@nwrddc03.gnilink.net...

Dale Parfitt

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Mar 19, 2004, 8:37:34 AM3/19/04
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" Tuuk" <bangkok...@yahoo.com> wrote in message
news:AgC6c.7250$R37....@read1.cgocable.net...

> Hi Dale
> Are there any websites or information available to explain more detailed
> about using antenna tuners for 2m ? I use two, one for 2m and one for
> 156megs frequently.
>
> The antenna tuner does bring the reflected power down to almost 0 to the
> radio and improves communications both receive and transmit. Could there
be
> a hidden damage or danger?
>
> Thanks
>
>Hi,
There is no hidden danger. Remember though that a coaxial cable's loss is a
sum of its loss when matched ( 1:1) plus an additional loss caused by VSWR
on the line.
1. A tuner at the rig does nothing to alter the VSWR on the coaxial cable
2. at HF, where line loss is already low and most times insignificant, the
increased loss caused by the VSWR is tolerable- thus thier popularity
3. At VHF the matched line loss ( the mfg specs) may become appreciable
unless large diameter cable or short runs are employed- this is where the
additional loss on the line caused by VSWR (unchanged by a tuner) can add
up quickly

The ARRL Antenna Handbook and probably the Handbook itself has a graph that
shows the additonal loss caused by VSWR on the cable as a function of
matched cable loss.


Dale W4OP


Scott Dorsey

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Mar 19, 2004, 10:36:02 AM3/19/04
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Tuuk <bangkok...@yahoo.com> wrote:
>Are there any websites or information available to explain more detailed
>about using antenna tuners for 2m ? I use two, one for 2m and one for
>156megs frequently.
>
>The antenna tuner does bring the reflected power down to almost 0 to the
>radio and improves communications both receive and transmit. Could there be
>a hidden damage or danger?

No damage or danger. But why not just fix the antenna? Making the antenna
present a proper load in the first place will give you much better results
than trying to fudge around a bad antenna with a tuner.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Reg Edwards

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Mar 19, 2004, 11:49:58 AM3/19/04
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> >The antenna tuner does bring the reflected power down to almost 0.

No it doesn't. It only brings the reading on the meter down to almost 0.
Do you really believe it?


Jim

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Mar 19, 2004, 11:58:18 PM3/19/04
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Uh... So I take it nobody has information on how to align a LAC-897?

Brian Goldsmith

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Mar 20, 2004, 1:34:15 AM3/20/04
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"Jim" wrote

Uh... So I take it nobody has information on how to align a LAC-897?

***** Why don't you tell us what exactly is wrong with the unit?

Brian Goldsmith.


Jim

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Mar 23, 2004, 10:22:31 PM3/23/04
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The problem is that I that the power output meter isn't giving me accurate
power out readings - it's reading too high. It has a bunch of trimmers in
it, and I don't want to make wholesale changes without the correct
instructions. I verified the swr with another bridge, it seems accurate
enough. have a shop manual for it?
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