Understand.
This radio was used when I got it Happened to check the 310 voltages one
day and found that most were around 1.5 (1.7 ?) volts. Some were as low as
0.5 volts.
Replaced some (from TT) and all came up to the higher value. That was a few
(5 ?) years ago. My impression at the time was that it cleaned up 40 and
80; note that very quantitative statement.
Just spot checked them a few weeks ago while doing something else, and saw
that a few (2 ?) had dropped to about 0.9...so I asked the question. Sort
of a purely academic question.
My impression is they work (have to) fairly hard (feel them) and maybe they
really do change - at least some of them.
Not paranoid about it...just curious.
My recollection is that TT recommends not replacing their diodes. Looked
into it once and found out that the diodes they use are kind of funny --- if
I remember correctly, they are described as pin diodes but really may not be
exactly ...think their recommended use was rf switching at VHF freq ?
We have had several excellent quantitative articles by several authors who
have highlighted the improvement which can be obtained by changing some of
the diodes in some rigs - rigs that we know have problems and ones which we
did not buy - perhaps exactly because of those problems.
I would not switch my diodes without some proof - quantitative - of
improvement.
My impression is that one must be careful with diode selection since
impedance in the on state, current requirements, etc are all important.
All pin diodes are not created equal and unless you select the right one and
'install' it properly you may be wasting your time...gee, wonder if you
could get a 'quieter' rig because your diodes weren't switched fully on!
Hope that helps
-----Original Message-----
From: patents@dx0man.prestel.co.uk <patents@dx0man.prestel.co.uk>
To: Steve Baron <stevebaron@starlinx.com>
Cc: TenTec <TenTec@contesting.com>
To: <tentec@contesting.com>
Date: Saturday, January 23, 1999 2:25 AM
Subject: RE: [TenTec] OMNI V J310's
>
>I'm intrigued by your query about the OMNI-V J310's. I have an OMNI-V
>and its now quite ancient. Are there any symptoms associated with
>J310 ageing ?? I feel, but cannot verify, that I've recently been
>getting more intermod than I used to get when the rig was newer,
>especially on 40m. Could be that the European QRM is a lot louder now
>I use ladder line instead of 100ft of coax, but it has occurred to
>me that I might also have a front end problem developing. The front
>end sensitivity on the HF (20 and up) bands appears to be low,
>although I can hear signals way down to the antenna noise if I crank
>up the RF gain. I cannot crank up the audio gain without getting
>noise of the wrong sort - not from the antenna. (My RF gain is usually
>well up, at 3-4 PM; audio stays down at 9-10 PM).
>
>The J310 is easily obtainable here, but I'm not sure how to set about
>matching a set of four. I think any replacement must use a well
>matched set, or it will defeat the object of sharing the work load.
>
>Incidentally, I replaced all the front end switching diodes with
>locally obtained pin diodes (not necessarily the best ones for the
>job - see recent comment on Paragon diode swap). This was before I
>discovered the obvious - I had a stuck reed relay !! There was no
>noticable performance improvement, even when I fixed the relay
>(with the help of the TT service dept).
>
>But I wonder if I should really be considering a complete re-alignment
>(is there any info on that available ?) after so much heavy use.
>
>73 John G3JAG
>
>
>On 20-Jan-99 Steve Baron wrote:
>>
>> A few years ago I noticed that the voltage on a few of the J10's
>> was
>> significantly lower (0.5 to 1 V) than the others which were up
>> around 1.5
>> (1.7 ?) or so. Replaced some and all were 'balanced'.
>>
>> Recently had the covers off and checked them again and saw that a
>> few had
>> dropped again.
>>
>> Would appreciate any input on the effect of reduced voltage - and
>> perhaps a
>> number for the lowest that should be tolerated.
>>
>> Thanks.
>>
>>
>>
>> --
>> FAQ on WWW: http://www.contesting.com/tentecfaq.htm
>> Submissions: tentec@contesting.com
>> Administrative requests: tentec-REQUEST@contesting.com
>> Problems: owner-tentec@contesting.com
>> Search: http://www.contesting.com/km9p/search.htm
>
>----------------------------------
>E-Mail: patents@dx0man.prestel.co.uk
To: <tentec@contesting.com>
>Date: 22-Jan-99
>Time: 14:03:35
>John Crux
>Consultant in product forgery - Asia and
>Africa
>
>----------------------------------
>
>--
>FAQ on WWW: http://www.contesting.com/tentecfaq.htm
>Submissions: tentec@contesting.com
>Administrative requests: tentec-REQUEST@contesting.com
>Problems: owner-tentec@contesting.com
>Search: http://www.contesting.com/km9p/search.htm
>
--
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