Radio Spares 8/16 DPDT switch

6string · Post by **6string** » Tue Jul 17, 2007 11:54 am

I posted this in the JTM 45 section, but thought it should go here as well...

Any of you guys used this with an RS tranny?

6string · Post by **6string** » Thu Jul 19, 2007 1:42 am

Well, The picture didn't show up in the original post, so here it is...

A simple way to switch between 8 and 16 ohms with a radio spares ot tranny.

Anybody tried this yet?

stevekostel · Post by **stevekostel** » Tue Jul 24, 2007 7:01 pm

Hi, I am thinking of it, too...

I was even able to get an 4 ohm arrangement
on a schematic using 2P3T switch,

RS OT looks something mysterious to me,
but I have found, that the 3 wiring diagrams
for 16, 8 and 4 ohm arrangement are basically this:

16 ohm - all three sections in series
8 ohm - one section in series with the other two in parallel
4 ohm - one section in parallel with the other two in series

For me, the most important question is this>

Does it matter, when I connect the sections in different order,
other then the exact one depicted in the schematics
in the transformers section?

Which means - are there another factors that come into play such
as capacitance between the sections or something else?

Well, I have not been able to find any answers to these question really,
so I hope anyone of you could help...

Steve

6string · Post by **6string** » Tue Jul 24, 2007 10:31 pm

I wrote an email to DST several weeks ago and the following is a portion of Bob's response...

"Keep in mind that all 3 windings are identical so the order isn't all that fussy. You just need to observe the correct polarity (winding start and finish). This applies to the primary as well."

Hope this helps...

I am going to go ahead and try it out on the build that I just started.

6string · Post by **6string** » Sun Aug 05, 2007 10:10 pm

I finished my build, and this DPDT 8/16 impedance switch works great. A really nice solution for Radio Spares OTs.