| Author |
Message |
    
Dx431
Senior Member
Username: Dx431
Post Number: 1050
Registered: 2-2002
| | Posted on Tuesday, May 31, 2005 - 12:52 am: | 
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Have a problem with new base setup. Here's the setup....
Old setup, A-99, 3 element beam flat on 50' tower, rg8x coax Kenwood 440s. SWRS 1.2 on both ants. New setup, MaCo V 5/8, rg213 coax Kenwood 440s.SWRS 1.2.
Ok, heres the problem.....
With a 20w unmodulated carrier on channel 20 I have a 1.2 swr on am.( flat swr with a 4w unmodulated carrier) Modulated carrier swrs are fine, 1.4 at the highest. On ssb the swr slams the meter?
Feedline and pl connectors are all new and soldered checked with an ohm meter, all good.
Never had this problem with the old setup.
What the heck is goin on here? I've never come across this before and has me puzzled.
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Chad
Intermediate Member
Username: Chad
Post Number: 295
Registered: 11-2004
| | Posted on Tuesday, May 31, 2005 - 9:22 am: |
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My SWR problem was due to harmonic emissions, The antenna is not tuned for the harmonics thus yielding a high reflected power. I would check the radio,
I assume you are re calibrating the swr meter for higher power, remember it's tough to get an SWR reading ob SSB but mine barely moves more and I understand your concern for it slamming to the right side! |
Alsworld
Advanced Member
Username: Alsworld
Post Number: 920
Registered: 1-2002
| | Posted on Tuesday, May 31, 2005 - 10:07 pm: |
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Dx431,
unless I am missing something, I think you are fine and without problem. I think Hollowpoint is correct and trying to measure SWR on SSB is futile. Measure the SWR on AM or FM only, and unmodulated.
I think you are okay.
Alsworld |
Crackerjack
Advanced Member
Username: Crackerjack
Post Number: 585
Registered: 7-2004
| | Posted on Wednesday, June 01, 2005 - 12:09 am: |
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No, that is modulation that requires a carrier.
For SWR you need to measure forward and reflected power. Some meters will measure SWR "real time" on SSB transmission. I have a "MFJ" that will.
Some DOSY meters will also measure SSB Modulation. Mine does not.
However, to set a tuner for lowest SWR, you had better use an unmodulated AM signal, just much sipmpler to do.
Also, cross needles FWD/REF power meters work best because -while the SWR reflected power is decreasing, you should see forward power increase at the same time. |
Chad
Intermediate Member
Username: Chad
Post Number: 297
Registered: 11-2004
| | Posted on Wednesday, June 01, 2005 - 9:16 am: |
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Regardless of how far one looks into this, if the SWR is fine with carrier, and modulated carrier and ssb performance is on par. Ten there is no reason to see the meter peg out. A little higher on the scale yes, rising halfway, maybe, but peg out? Not unless something is drastically raising the power output on SSB. |
Road_warrior
Advanced Member
Username: Road_warrior
Post Number: 611
Registered: 7-2004
| | Posted on Wednesday, June 01, 2005 - 10:52 am: |
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Yes, you need a carrier to measure VSWR.
You are probably worrying about a problem
that does not exist.
JIM/ PA/ CEF 375 |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 451
Registered: 9-2004
| | Posted on Wednesday, June 01, 2005 - 10:43 pm: |
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"these meters cannot measure at an audio rate"
you are trying to misuse your meter and are worrying about its readings. read the swr on am with the mic gain all the way down. check it on the highest power level that you have; it shouldnt have changed much if any. if you have these results you are fine.
my solution is quite simple.
STOP LOOKING AT YOUR METER WHEN YOU ARE ON SSB.
BTW, it was nice to talk to you in your mobile DX431. hope to make contact again in the future.
matt |
Dx431
Senior Member
Username: Dx431
Post Number: 1066
Registered: 2-2002
| | Posted on Sunday, June 19, 2005 - 11:42 pm: |
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Ive been into radio for over 25yrs, I think I know what I'm doin. Theres nothin wrong with my meters. The problem is,the verticle element is to long and the ring is set incorrectly. Sooooo.....it is resonating on the wrong band and the impedenace is to high.
How did I come to this conclusion?
Quite simple. I took a good look at the ring and discovered that the ring is bent and by rereading the instructions I found that I mismeassured the verticle element. Simple mistake.
Solution:
Remeassure the verticle element and reset the ring.
Just that easy! 
Now, I need to find someone to climb the tower and take the ant down so I can fix it! 
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Dx431
Senior Member
Username: Dx431
Post Number: 1069
Registered: 2-2002
| | Posted on Tuesday, June 21, 2005 - 1:55 am: |
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I do know how to read a SWR meter and I'm not checking it on SSB. I'm checking it on AM. Even in AM mode, the swrs should not change much if at all when modulation is applied.But when I apply modulation and the SWRs jumps to 2.5-3.0 on AM and into the red on SSB, that tells me there's a problem.
At any rate, I know what the problem is and I know how to fix it.
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Dx431
Senior Member
Username: Dx431
Post Number: 1070
Registered: 2-2002
| | Posted on Wednesday, June 22, 2005 - 1:33 am: |
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I give up!
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Bruce
Senior Member
Username: Bruce
Post Number: 2878
Registered: 9-2003
| | Posted on Wednesday, June 22, 2005 - 6:51 am: |
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Maby i'm wrong but reading VSWR while your modulation a radio would be near impossable. When you modulate a AM signal the output will go up and your set point for the VSWR would also go up resulting in a higher reading on the meter as you talk. The only way you could even start to get the right reading would be if your meter could " TRACK " the changing output and remain calabrated as you talk. |
Dx431
Senior Member
Username: Dx431
Post Number: 1071
Registered: 2-2002
| | Posted on Wednesday, June 22, 2005 - 12:31 pm: |
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Ok, I'm gonna try this one more time...........
When I check my SWR, it is with a 4w unmodulated carrier on AM. I get a 1.2. Great! Woohoo!
Now, I do understand that the swr will change with modulation. And I do know I have to recalibrate the meter when using higher power. Ok Einstein, tell me this,why does the SWR jump to 2.5-3.0 with modulation?
I did not have those type of readings with my Antron/beam setup.
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Tech808
Moderator
Username: Tech808
Post Number: 6155
Registered: 8-2002
| | Posted on Wednesday, June 22, 2005 - 5:34 pm: |
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DX431 / Jason
I copied and e-mailed Tech833 / Paul Tech833@copperelectronics.com your Question and here is his Reply for you.
He has an intermittent connection going 'diode' on him. He will probably
have to take the antenna down and disassemble it then sand everything down
and reassemble to fix this.
Also, that coax might have a little hair of the coax shield getting close to
center conductor and arcing. Tough call on this one! Either way, redo it.
Sorta the 'shotgun' approach.
Paul
When I do not know or have an answer to a question or cannot offer help, I ask those who have more experience than myself.
And Tech833 is #1 at the TOP of that list when it come's to Antennas.
Hope this help's,
Lon
Tech808
CEF808
N9OSN
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Dx431
Senior Member
Username: Dx431
Post Number: 1072
Registered: 2-2002
| | Posted on Thursday, June 23, 2005 - 1:33 am: |
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Thank you!! |
Chad
Intermediate Member
Username: Chad
Post Number: 341
Registered: 11-2004
| | Posted on Thursday, June 23, 2005 - 8:43 am: |
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I still vote harmonics.
But that's just me  |
Tech808
Moderator
Username: Tech808
Post Number: 6160
Registered: 8-2002
| | Posted on Thursday, June 23, 2005 - 11:07 am: |
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OK Everyone,
There is nothing to vote on here or to debate.
And it make's no difference if you agree or disagree with what another member has posted as a helpful suggestion.
Dx431 posted a problem he has, and asked for suggestion's/help.
Everyone will have different suggestion's/idea's on how to help solve the problem.
If you made a post above offering advice or help on solving the problem then Dx431 has read it and has many option's to choose from to help solve the problem and that should be the end of it.
Thank's
Lon
Tech808
CEF808
N9OSN
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Dx431
Senior Member
Username: Dx431
Post Number: 1074
Registered: 2-2002
| | Posted on Thursday, June 23, 2005 - 12:43 pm: |
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This is the last I will post on this subject.
I will do as Tech833 said, which is what I was going to do before I started this thread, but, was lookin for opnions/ideas.
From now on when/if I have any future ant. problems, I will consult Tech833.
DX431
CEF106
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Airplane1
Intermediate Member
Username: Airplane1
Post Number: 455
Registered: 5-2004
| | Posted on Thursday, June 23, 2005 - 2:04 pm: |
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Tech 833 knows his stuff!!!
AP |
123upmichigan
Intermediate Member
Username: 123upmichigan
Post Number: 110
Registered: 8-2002
| | Posted on Friday, June 24, 2005 - 10:36 am: |
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glad to see you got it straightened out jason, my initial response to you in yahoo was also incorrect, but mine ended up being a ground issue on the beam. grounded all the equipment in the shack and put a ground field in and it brought the swr down to about 1.4 then picked up a mfj 945e tuner and brought it down the rest of the way. and btw i found out the dosy meter was reading incorrect |
Alsworld
Advanced Member
Username: Alsworld
Post Number: 933
Registered: 1-2002
| | Posted on Friday, June 24, 2005 - 11:41 pm: |
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Jason,
this was actually quite an interesting post even with the debates a bit heated.
I figured I had to be missing something because I also missinterpreted what you were saying initially. But, I knew that you knew what you were doing, and had seen a change, so there was a lot of ideas changing hands back and forth.
Actually, I did not know the answer but can see where this thread can help others in the future who run up against this same phenomenon.
That is why this forum is here and thanks for sticking with this thread even though you were getting frustrated. I think I may have learned something although still deciphering the info (I'm a little slow sometimes LOL!). Good stuff for sure.
Alsworld |
