Well, thanks, Colin.
I'm obviously getting varying opinions on whether to leave the excess coax
for the 160 meter sloper there or not, but maybe I will remove it at some
point, just to be able to use the extra coax for another purpose, if nothing
else.
And, again, your additional comments on the analyzer accuracy are very very
useful.
Once again, I appreciate everyone's input on this problem, and will keep you
posted as I learn more.
73 from Tom Behler: KB8TYJ
----- Original Message -----
From: "colin McDonald" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, November 12, 2011 4:33 AM
Subject: Re: Need helping making sense out of contradictory SWR readings
> seems like there are allot of factors that could be interphereing with an
> accurate reading by the annalizer.
> I would definitely cut off that excess 40 feet of coax though...no need in
> having that much laying around...causing issues somewhere in the system.
> I'm not too sure MFJ annalizers are all that super accurate either since
> I've seen a few of them give kind of odd ball readings on stuff that was
> known to be tuned.
> When our club repeater manager guy hooked up the 30000 dollar annalizer to
> an antenna, it showed it was tuned and resonant on a particular frequency,
> then the MFJ 269 claimed a 6 to 1 swr on that same frequency...
> Those annalizers are generally useful, but I think sometimes the good old
> SWR meter is more valuable as a true or at least, more accurate reading
> device.
> Where the annalizer really shines in my mind is finding the resonant point
> of an antenna, before putting it up and feeding it with coax and all the
> rest...makes tuning an antenna so much easier if you know if it's too
> short
> or too long before you get it up to height.
>
> Regards
> Colin
> ----- Original Message -----
> From: "Tom Behler" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Friday, November 11, 2011 8:00 PM
> Subject: Re: Need helping making sense out of contradictory SWR readings
>
>
>> Mike:
>>
>> You have a very interesting point here about local broadcast signals.
>>
>> I happen to live about a half mile from the tower for the only commercial
>> A
>> M radio station in our little Michigan town. ... It broadcasts on 1460
>> AM,
>> with a night-time power of, I believe, 1000 watts.
>>
>> Are you saying that this is what's messing the analyzer up?
>>
>> Again, just to be sure I'm understanding you, are you saying ignore the
>> analyzer, and just go with what my TW1 and TS590 meters are saying?
>>
>> Obviously, my 160 meter antenna is still too long electrically, so that
>> will
>> need to be shortened.
>>
>> But, here's another question: When we put up the 160 meter sloper, I
>> only
>> had a 100-foot piece of RG8X coax to connect between the antenna and the
>> rig, which gives me about 40 feet of excess coax. ... Should I cut that
>> coax
>> to only what I need? Would that change anything?
>>
>> Again, you are giving me some very interesting observations here.
>>
>> 73 from Tom Behler: KB8TYJ, Big Rapids, MI
>>
>>
>> ----- Original Message -----
>> From: "Mike Cozzolino" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Friday, November 11, 2011 9:30 PM
>> Subject: Re: Need helping making sense out of contradictory SWR readings
>>
>>
>>> hello tom, the analyzer is almost useless on 160 and 80m
>>> antennas. the reason is because you have so much broadcast signals
>>> coming down the feed line that the analyzer is all messed up. in
>>> areas where folks don't have the broadcast crap the analyzer does the
>>> fine job. so go by the swr bridge and ignore the analyzer. even a
>>> swr bridge is influenced by the length of the feed line, you could
>>> have a 1:1 some where along the coax where the swr is really much
>>> higher. the only way to use an swr bridge is through a electrical
>>> half wave to the antenna or with the swr bridge at the feed
>>> point. you can also use multiple electridal half waves between the
>>> swr bridge and the ant. take care, c u 73 mike
>>>
>>>
>>>
>>> At 05:28 PM 11/11/2011, you wrote:
>>>>Hi, folks.
>>>>
>>>>Well, I have managed to get hold of an MFJ 259B antenna analyzer to help
>>>>try
>>>>to figure out what is going on with my 80 meter and 160 meter sloper
>>>>antennas that we put up a few weeks ago.
>>>>
>>>>However, when taking some preliminary readings with the analyzer
>>>>tonight,
>>>>and comparing them against what my TW1 watt meter and the SWR meter on
>>>>the
>>>>TS590 say, I am getting very confusing results.
>>>>
>>>>Let me give a few examples:
>>>>
>>>>On 80 meters, my sloper has an SWR of about 5 to 1 on the top and bottom
>>>>of
>>>>80 meters, with a dip of 1.0 to 1 around 3.887 mhz. But, when we put
>>>>the
>>>>analyzer on the antenna, it shows the lowest SWR to be about 1.3 to 1 at
>>>>3.887 MHZ, but the SWR's skyrockets quickly on either side of that null
>>>>to
>>>>infinity on the lowest part of the band, and to over 8.1 to 1 on the top
>>>>of
>>>>the band.
>>>>
>>>>With my 160 meter sloper, my lowest SWR is about 5 to 1 at the very
>>>>bottom
>>>>of the band, according both to my TW1 and the TS590 SWR meter, but the
>>>>needle on the analyzer doesn't even budge when tuning through the entire
>>>>band, and stays up at some ungodly figure of an SWR of about 20 to 1.
>>>>
>>>>I just checked for a short on my coax feed lines, and there does not
>>>>appear
>>>>to be any problem there.
>>>>
>>>>We are using fresh batteries in the analyzer which were just bought
>>>>tonight.
>>>>
>>>>Are we perhaps not adjusting the analyzer correctly?
>>>>
>>>>I am sure that, to some, all of this seems very elementary, so please
>>>>bare
>>>>with me while I do some learning here.
>>>>
>>>>73 from Tom Behler: KB8TYJ
>>>
>
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