Re: Ping Patrick (was Re: FA: Pair New Heyboer 40W SE Output Transformers for EL34):

In article <4756A230.837379D2@xxxxxxxxxxxxxxxxxx>,
Patrick Turner <info@xxxxxxxxxxxxxxxxxx> wrote:

John Byrns wrote:

In article <C378FC52.A1FA1%jono_1@xxxxxxxxxxxxx>,
Jon Yaeger <jono_1@xxxxxxxxxxxxx> wrote:

I'm selling a pair of new trannies for a single-ended SE amplifier, rated
at
40W and continuous DC offset current of 100 mW.

These are made by Heyboer - the same folks who wound Eico iron and other
amplifier designs.

Each has 10 secondary taps and is very unusual.

Thanks for looking!

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290188125461

I love how the eBay description of the secondary connections for this
OPT.

"The lowest load applied to any secondary tap will be 4 ohms, and two
loads will be applied simultaneously to achieve a 2.5K reflected
impedance on the primary, with the power split between the two loads,
therefore, the wire size will not have to be made inordinately large.
One load will always be 16 ohms (or not connected), and the other will
be either 4, 8, or 16 ohms."

Maybe Patrick can explain this secondary connection scheme for us in a
way mere mortals can understand it?


The description you quote is by a technically illiterate vagabond,
and cannot be deciphered, and need not be attempted.

These OPT have a jpg document also in the pictures,
and there you might be able to read the original maker specs.

The "technically illiterate vagabond" appears to be the transformers
maker, as the quote comes directly from the "jpg" of the "original maker
specs.". The "jpg" also includes a table showing different load
combinations, except that it stupidly omits any information on which of
the eleven secondary leads the loads should be connected to for each
combination! It appears from the "jpg", which is a little too blurry to
be absolutely sure, that the secondary is connected as one continuous
winding with ten taps, so there is no opportunity for paralleling
secondary sections.

One can only but wonder what this thing was originally designed for,
perhaps Jon knows? If it weren't for the secondary design it would be a
tempting buy at $100.00 for the pair.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/
.

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