K2 T4 winding ratio

[Don Wilhelm-4]

  Hi and sorry about the bandwidth.

I recall receiving a query about the T4 alternate winding ratio within
the past week, but cannot locate the email to respond properly.

The normal winding ratio for T4 is to be used.  It must NOT be used if
the KSB2 option is installed.

In other words, it can only be used with a CW only, QRP only (at 5 watts
or less) type K2.

While the alternate QRP winding of T4 may produce greater efficiency at
the 5 watt level, if used at levels above 5 watts, the efficiency is
actually reduced.

In other words, I do not recommend that the alternate ratio for T4 be
installed on any K2.  I have seen several that have this modification
that have been sold, and the buyer adds the KSB2, then wonders why the
K2 "acts funny in transmit" when used for SSB.

If the original person asking this question has any more questions,
please contact me off-list.

73,
Don W3FPR
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[Don Wilhelm-4]

  Sorry again.

Reading my own email, I discovered a problem.
The standard winding ratio is the ONLY one to be used with the KSB2
option installed.  The "increased efficency at 5 watts" ratio is only
for CW and at power levels of 5 watts or less.  The efficiency at
greater power levels is less than using the standard ratio.

73,
Don W3FPR

On 3/15/2011 11:02 PM, Don Wilhelm wrote:

>    Hi and sorry about the bandwidth.
>
> I recall receiving a query about the T4 alternate winding ratio within
> the past week, but cannot locate the email to respond properly.
>
> The normal winding ratio for T4 is to be used.  It must NOT be used if
> the KSB2 option is installed.
>
> In other words, it can only be used with a CW only, QRP only (at 5 watts
> or less) type K2.
>
> While the alternate QRP winding of T4 may produce greater efficiency at
> the 5 watt level, if used at levels above 5 watts, the efficiency is
> actually reduced.
>
> In other words, I do not recommend that the alternate ratio for T4 be
> installed on any K2.  I have seen several that have this modification
> that have been sold, and the buyer adds the KSB2, then wonders why the
> K2 "acts funny in transmit" when used for SSB.
>
> If the original person asking this question has any more questions,
> please contact me off-list.
>
> 73,
> Don W3FPR
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

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