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

[carl at UDel.Edu]

This would be correct.  I was expecting any difference between the on-board SWR meter and an external SWR meter to be relatively close when using a dummy-load for the load.  In fact, after I posted, I did the same comparison with my FT-897D.  The on-board SWR meter on the 897D gave an SWR of 1.0:1 on all bands, completely in line with the external SWR meter.  Now, of course, this could mean that the SWR meter on the 897D is not sensitive enough to pick up minor mismatches due to inferior coax, and the such, or it could mean there is a problem with the SWR meter on the Mark-V Field.

What I am trying to determine is whether anyone else has noticed this kind of discrepancy with any version of the FT-1000MP series (presuming they are all using the same circuitry for the on-board SWR meter).  Additionally, is the on-board SWR meter so sensitive as to notice mismatches and/or impedances on small sections of coax (2-4 feet at most)?

Thanks for the input, it is greatly appreciated!


Best Regards,
Carl - K3NTH


>------------------------------
>
>Message: 3
>Date: Tue, 22 Jan 2008 17:09:19 -0500
>From: "Bob Main" <bobmain1 at alltel.net>
>Subject: RE: [1000mp] SWR Problems with Mk-V Field
>To: "'All about Yaesu 1000mp'" <1000mp at mailman.qth.net>
>Message-ID: <000601c85d43$6fe575c0$0f0aa8c0 at grumpy>
>Content-Type: text/plain;	charset="us-ascii"
>
>Probably the inconsistency of the readings of the two units.
>
>-----Original Message-----
>From: 1000mp-bounces at mailman.qth.net [mailto:1000mp-bounces at mailman.qth.net]
>On Behalf Of Jerry Spring
>Sent: Tuesday, January 22, 2008 4:50 PM
>To: All about Yaesu 1000mp
>Subject: Re: [1000mp] SWR Problems with Mk-V Field
>
>So what's the problem?
>
>
>--- 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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