[1000mp] Re: SWR Problems with Mk-V Field

Fri Jan 25 20:40:03 EST 2008

I wanted to take a moment to thank Mike for posting this, he beat me to the punch! :-)  I also wanted to thank all those who lent me their thoughts and suggestions they were/are greatly appreciated.

One final comment, I also sent a note off to Byron Campbell, WA4GEG, whom many of you know, and from whom, like me, you have gotten great service work on your 1000MP radio.  Byron responded in the following way:

"Hi Carl,

It is possible in the near future that the micro processors in ham 
transceivers will become fast enough to calculate accurate SWR during PEP 
modes (SSB) -- but we are not there just yet:o) 

So with the MP series gear one should always use steady state (CW) RF carrier 
for all SWR measurements. 25~35 watts is plenty for accurate measurements. 
Under high SWR conditions, i.e. 2.0:1 and greater, even 10 watts CW will 
suffice."

Which confirms what Mike had said.  This has been extraordinarily useful information to me!  Thank you again to all of you!

Best Regards,
Carl - K3NTH

Message: 2
Date: Fri, 25 Jan 2008 08:26:25 -0500
From: "Mike Schatzberg" <cherokeehillfarm at earthlink.net>
Subject: Re: [1000mp] Re: SWR Problems with Mk-V Field 
To: "All about Yaesu 1000mp" <1000mp at mailman.qth.net>
Message-ID: <007e01c85f55$e2f253d0$6401a8c0 at mike>
Content-Type: text/plain;	charset="iso-8859-1"

Hello 1000MP Fans:

I just wanted to take a minute to update this thread.

Carl now reports that using low level steady carrier, he now achieves
readings of 1.0:1 from the on-board SWR meter on all bands, except 10m,
where it is 1.1:1.

His original higher readings were taken in the SSB mode, with 100 watts PEP
output, and these readings were indeed troublesome to him.

I can't really say that I have an explanation yet for the spiking of SWR
values as seen while operating on SSB, but I know that the issue exists.  In
the meantime, it seems that this is the normal condition to see while
monitoring SWR while transmitting on SSB.

73 and Happy DXing,

Mike
W2AJI

----- Original Message ----- 
From: "Mike Schatzberg" <cherokeehillfarm at earthlink.net>
To: "All about Yaesu 1000mp" <1000mp at mailman.qth.net>
Sent: Wednesday, January 23, 2008 1:04 PM
Subject: Re: [1000mp] Re: SWR Problems with Mk-V Field

>Hello Carl:
>
>I connect my SWR bridge couplers directly to the radios with a double male
>connectors, I also do the same with my amplifiers, the couplers are
>connected exactly in the same way.  I use no coax at all.  The coax used
>between the coupler and the dummy load should be short and of high

quality,

>with good connectors.
>
>When checking SWR with the Mark V, I find the most accurate readings to be
>taken in CW mode, while sending a series of dits, with perhaps 30 watts or
>so of output.  You will notice that the readings will be different for

SSB,

>if you try to take measurements in that mode also.
>
>I find excellent agreement between my outboard SWR measurement and the on
>board meter using this method.
>
>Should you be driving an amplifier, the cabling between the amp and the
>driver is another special case, in order to obtain the lowest possible

input

>SWR into your amp without the use of your on board tuner.  There is an
>article on my website which addresses this issue which you may find
>interesting.
>
>73 and Happy DXing,
>
>Mike
>W2AJI
>http://home.earthlink.net/~cherokeehillfarm/id2.html
>
>
>----- Original Message ----- 
>From: <carl at UDel.Edu>
>To: <1000mp at mailman.qth.net>
>Sent: Wednesday, January 23, 2008 11:05 AM
>Subject: [1000mp] Re: SWR Problems with Mk-V Field
>
>
>>Dear Ron,
>>
>>Thanks for the input!  Originally, I had 2 ft of RG-8 going from the
>
>Mark-V Field to an antenna switch, and then 2 ft of RG-58 going from the
>switch to the external watt-meter/SWR meter, and then 2 ft of RG-58

attached

>to the dummy-load.  With your thoughts in mind, I went ahead and
>disconnected all of this and attached the dummy load directly to the

Mark-V

>Field via 2 ft of RG-8, and everything stayed the same, except everywhere

is

>was 1.4:1 came down to 1.3:1, and on 10-meters, the SWR went from 1.3:1 to
>1.4:1.  It may be that the on-board SWR meter is just sensitive to the

coax

>used (the coax is commercial, but obtained through a local CB supplier);

on

>the other hand, it might be an indication of a problem developing.  Just
>wondering what others have experienced.
>
>>Thanks again, Ron, it is greatly appreciated!
>>
>>
>>Best Regards,
>>Carl - K3NTH
>>
>>>Message: 4
>>>Date: Tue, 22 Jan 2008 19:15:11 -0500
>>>From: W4LDE-Ron <w4lde at cfl.rr.com>
>>>Subject: Re: [1000mp] SWR Problems with Mk-V Field
>>>To: All about Yaesu 1000mp <1000mp at mailman.qth.net>
>>>Message-ID: <4796870F.90402 at cfl.rr.com>
>>>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>>
>>>Carl,
>>>
>>>The change may be caused by the length of the coax between the rig and
>>>the remote tuner.  I had a similar difference in readings using
>>>manufactured coax w/ connectors between the amplifier and the rig and
>>>the amplifier and the remote tuner.  See if you have some different
>>>lengths of coax and see what readings you get.  I average about .2
>>>differences after I changed the lengths.  Frankly I think that you will
>>>never see the same readings and from your data below that meters are
>>>within tolerances.
>>>
>>>73 de
>>>Ron W4LDE
>>>
>>>carl at UDel.Edu wrote:
>>>
>>>>I have a Mark-V Field hooked up to a G5RV and matched with a LDG
>
>AT200Pro autotuner.  I noticed the other day that my autotuner and my
>external watt-meter were claiming a 1:1 match, but the SWR meter on the
>Field was claiming 1.7:1.  While I don't expect everything to always read
>identical, I thought this rather strange.  I switched to a 50 ohm
>dummy-load, and did some investigating using the dummy-load:
>
>>>>160m - 1.1:1
>>>>80m - 1.1:1
>>>>40m - 1.0:1
>>>>20m - 1.3:1
>>>>17m - 1.4:1
>>>>15m - 1.4:1
>>>>12m - 1.4:1
>>>>10m - 1.3:1
>>>>
>>>>All of these values were read from the SWR meter on the Mark-V Field;
>
>the autotuner and my external watt-meter/SWR meter are reading 1.0:1 on

all

>bands  Might this be an indication of a problem, or have others noticed

this

>discrepancy?  Any feedback would be most appreciated!
>
>>>>
>>>>Thanks, and 73's!
>>>>
>>>>Carl - K3NTH
>>>>______________________________________________________________
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>>>>
>>>>
>>>
>>______________________________________________________________
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