K2 Toroids Latest?

[Deni F5VJC-2]

 
Hi Vic and all.
 
I have kept my K2 (1188) up to date with all the A/B mods, however at times
I see references such as the one below about T7  where a  toroid may have
been changed from the original windings to a revised spec. Are these
documented anywhere, which toroids are now different and why?
 
Thanks,
 
73, Deni
 
F5VJC / GM3SKN
 
K21188
 
=========================================================================
It looks fine, although I would move the two wider filters a bit to the
right.
There looks like about 6-8 db difference in attenuation between the widest
and
narrowest filters, which is probably on the high side of normal (although
this
tends to vary).  I see about 4 db on mine, which is #709 but has had the
crystals replaced and T7 rewound to current spec.
 
I would be interested in knowing how much difference in attenuation others
are
seeing.  I know that K1JD has an ANCIENT K2 (field test vintage) which has
zero
db difference!
 
--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
 


 
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[Don Wilhelm-3]

Deni,

T7 is the only transformer that will make any difference.  If it is wound
with a 13:3 turns ratio it can be rewound with a 20:5 ratio for a better
impedance match to the IF filter.

The number of turns on bifilar wound T3 has been reduced in later K2s, but I
have not noticed any difference (including the RF levels on my 'scope) after
changing it on several K2s.

73,
Don W3FPR

> -----Original Message-----
>
> I have kept my K2 (1188) up to date with all the A/B mods,
> however at times
> I see references such as the one below about T7  where a  toroid may have
> been changed from the original windings to a revised spec. Are these
> documented anywhere, which toroids are now different and why?
>

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[Sverre Holm]

-----Original Message-----
I have kept my K2 (1188) up to date with all the A/B mods, however at times
I see references such as the one below about T7  where a  toroid may have
been changed from the original windings to a revised spec. Are these
documented anywhere, which toroids are now different and why?
--------------------------

I have updated the mods list on
http://www.qslnet.de/member/la3za/K2/mod.html and the section on pre-3000
series mods (press section 3) on status of T3 and T7.

My search of the mail list gave as a result that they both were changed to
their current turns numbers in K2 manual rev C (19 April 2000). If anybody
has more accurate info on which serial number the changes first applied to,
I will update with that info. My guess is somewhere in the 1000-1500 range.

Note also that the mods list on www.qsl.net has now been removed and it is
only to be found on the www.qslnet.de

73

Sverre
LA3ZA
http://www.qslnet.de/la3za/
 
 

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