[UK-CONTEST] UK-Contest Digest, Vol 36, Issue 17
Stewart Baker
stewart at baker.nildram.co.uk
Sun Dec 25 03:51:32 EST 2005
On Sat, 24 Dec 2005 12:00:45 -0500, uk-contest-request at contesting.com wrote:
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> Today's Topics:
>
> 1. Re: FT1000MP MkV Shift and Width Controls (Douglas Maxwell)
> 2. Samlex SEC1223 (Clive Whelan)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 24 Dec 2005 08:53:54 -0000
> From: "Douglas Maxwell" <douglas.maxwell at virgin.net>
> Subject: Re: [UK-CONTEST] FT1000MP MkV Shift and Width Controls
> To: "Paul G3WYW" <paul at kbcomms.demon.co.uk>
> Cc: uk-contest at contesting.com
> Message-ID: <001801c60867$91bd6500$0200a8c0 at cnew>
> Content-Type: text/plain; charset=iso-8859-1
>
> Hi Paul,
> I also posted the article at the following address:
>
> http://2m0vlf.proboards57.com/index.cgi?board=discussion&action=display&thread
=1
> 135185890
>
> The formatting seems to have been stripped from the diagrams I posted to the
> group. I was beginning to think I was the only one who thought it needed
> further explanation. I wanted to be able to adjust these controls and get it
> right first time, instead of the suck it and see approach. The trouble is
> that the change these controls make is difficult to quantify due to the
> number of variables:
>
> IF stage filter combinations i.e. 500/none, 500/500, 250/none, 250/250 etc
> Filter widths
> Filter types i.e. Mechanical, crystal
> Menu settings i.e. DSP or analogue demodulator, DSP receive width 100-3100
> or 300-2800, 10 or 20Hz for shift control etc.
>
> The diagrams aren't the best, but let me know if you agree or disagree with
> them.
>
> Cheers
>
> Doug
>
>
> ----- Original Message -----
> From: "Paul G3WYW" <paul at kbcomms.demon.co.uk>
> To: "Douglas Maxwell" <dcmaxwell at iee.org>
> Sent: Friday, December 23, 2005 11:46 PM
> Subject: Re: [UK-CONTEST] FT1000MP MkV Shift and Width Controls
>
>
>> Hi Doug,
>>
>> Not sure whether you have had any responses to your email, but I had some
>> trouble understanding your diagrams. My email server seems to have removed
>> any formatting information so the diagrams look wierd and not easy to
>> understand.
>>
>> Can you please send me them again, perhaps inside a word document or a
> .zip
>> file where the information is not lost.
>>
>> Best Regards
>>
>> Paul g3wyw
>>
>>
>> ----- Original Message -----
>> From: "Douglas Maxwell" <douglas.maxwell at virgin.net>
>> To: <uk-contest at contesting.com>
>> Sent: Wednesday, December 21, 2005 12:24 PM
>> Subject: [UK-CONTEST] FT1000MP MkV Shift and Width Controls
>>
>>
>> Hi all,
>> When I look at the manual for the MkV, I always get stuck on the
>> pictorial description of the shift control operation. I think it's wrong.
> My
>> own method for picturing the action of these controls is the following
>> (frequency increases toward the right):
>>
>> USB
>> __________
>> __________________|___/ \___ No Shift
>> __________
>> __________________|/ \_____ CCW Shift
>> __________
>> __________________|______/ \ CW Shift
>>
>>
>> __________
>> __________________|___/ \___ No Width
>> ________
>> __________________|______/ \___ CCW Width
>> ________
>> __________________|___/ \_____ CW Width
>>
>> LSB
>> __________
>> ___/ \___|_________________No Shift
>> ___________
>> / \ _____|________________ CCW Shift
>> __________
>> ______/ \|________________ CW Shift
>>
>>
>> __________
>> ___/ \___|_________________No Width
>>
>> _________
>> _____/ \___|_________________CCW Width
>>
>> ________
>> ___/ \_____|_________________CW Width
>>
>>
>> As can be seen from the above diagrams, in either USB or LSB the action of
>> both controls is constant i.e.
>> 1) The shift control moves the passband in the direction it is rotated.
>> 2) The width control brings in the skirt of the passband it is rotated
>> toward.
>>
>> Audio frequency is mode dependant, so to get rid of interfering signals it
>> helps me to imagine the following:
>>
>> LSB USB
>> __________ __________
>> ___/ \___|___/ \___
>> H L L H
>>
>> Therefore:
>> USB
>> 1) Higher pitched interfering signals will be above you in frequency.
>> 2) Lower pitched interfering signals will be below you in frequency.
>> LSB
>> 1) Higher pitched interfering signals will be below you in frequency.
>> 2) Lower pitched interfering signals will be above you in frequency.
>>
>> With a bit of practice you can now hear the interfering signal and know
>> which way to rotate the shift, width or shift/width controls to
> effectively
>> eliminate it.
>>
>> If you need to get rid of interfering signals on both sides.
>> USB
>> Both shift and width controls turned CCW.
>> LSB
>> Both shift and width controls turned CW.
>>
>> The effectiveness of the width control is dependant on wither both 2nd and
>> 3rd IF filters are fitted, but with both fitted (and with menu 1-2 shift
>> step = 10Hz) each graduation mark equates to approx 250Hz worth of change.
>> This means that for USB CW with cascaded 500Hz filters and shift and width
>> both CCW by 1 graduation you have almost closed the passband. Try 1/2
>> graduation mark in this situation for weak signal work and you have an
>> effective 250Hz filter.
>>
>> I hope that this will encourage more people to explore their MkV as it is
> a
>> truly awesome machine when used to the utmost of it's capabilities. I hope
>> it also dispels the myth that you must have a MkV fully loaded to get any
>> performance from it.
>>
>> P.S. I use the free DX LAB software suite for experimenting, in particular
>> Winwarbler's PSK31 waterfall to observe shift and width effects. Also a
>> lesser known fact, that the C-IV commander software that also comes
> bundled
>> allows individual control of 2nd and 3rd IF filter insertion. This means
>> with both 500Hz filters installed and with rig control enabled you can
>> choose whether you wish 2nd, 3rd or 2nd and 3rd filters in-line.
>>
>> Have a Merry Christmas all
>>
>> Doug
>> GM0ELP
>>
>>
>> --------------------------------------------------------------------------
> ------
>
>>
>> Internal Virus Database is out-of-date.
>> Checked by AVG Free Edition.
>> Version: 7.1.371 / Virus Database: 267.13.13/199 - Release Date:
> 12/13/2005
>>
>>
>> --------------------------------------------------------------------------
> ------
>
>>
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>> Version: 7.1.371 / Virus Database: 267.13.13/199 - Release Date:
> 12/13/2005
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>
> --
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> Checked by AVG Free Edition.
> Version: 7.1.371 / Virus Database: 267.14.7/214 - Release Date: 12/23/2005
>
>
> ------------------------------
>
I brought a Samlex SEC1223 PSU about 2 months ago from W & S.
The unit performs perfectly, and I can find no trace of switch mode noise on
any HF band.
I took the cover off and noticed that it had Ferrite beads and capacitors fitted
as per a German mod to cure LF interference.
Go for it...
73
Stewart G3RXQ
> Message: 2
> Date: Sat, 24 Dec 2005 16:45:37 -0000
> From: "Clive Whelan" <clive.whelan at btinternet.com>
> Subject: [UK-CONTEST] Samlex SEC1223
> To: <uk-contest at contesting.com>
> Message-ID: <NJEKIHLAGJFHHNGLLDFMGEIAFEAA.clive.whelan at btinternet.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
> I have had a couple of reccos. for this PSU to address my trigger happy
> problem with the Nissei and the IC7400.
>
>
> So far so good. However, the eham.net reviews cite serious switch mode noise
> problems on 80&40m, although most don't mention it, and give it 5/5.
>
> Does anyone else here have experience of the unit, particularly in respect
> of switch mode noise?
>
> 73
>
> MX es HNY
>
> Clive
> GW3NJW
>
>
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> End of UK-Contest Digest, Vol 36, Issue 17
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