Hi Glenn and AMPS folks,
The Yaesu power supply that you are referring to has got to be the
FL2000/2100 voltage doubler supply, with which I'm intimately familiar.
I have an old FL2000B, which is now an FL2000/QB (if you want to know what
that is, read on....).
Secondary resistance is 19.5 Ohms! apparentlly with no ill effects. The
transformer is rated at 850Watts. Later models (FL2100xx) use the same core
for HV as well as filament/utility, "stealing" some 60W from B+! FL2000B has
a separate filament/utility voltage transformer, leaving the entire core
capacity for B+)
When I performed the change from the /B to the /QB suffix (Out went the
572Bs and in a single QB4/1100 - yes it is possible!), I also wired the
primary so as to get the highest possible secondary voltage, the two 100V
primary in series fed from our 230V net. yielding approx. 950V secondary (No
load). resulting B+ is 2830V (no load); 2750V idling; and 2450-2500V at
700W+ out (400mA)
Of cause the nearly 30 years old caps didn't last long at this, and I had to
find replacement that would fit into the rather cramped space! I went for 8
x 220uF/400VWV, that would fit into the same space as three of the old caps,
in the process I gained an increase in capacity from 12.5uF to 27.5uF, which
in my opinion has made the B+ regulation a lot better and the power supply
much stiffer. Alas, should the big bang happen then......... Buyer beware!
i have put in a current limiting resistor in B+)
Vy 73 de OZ1PIF, Peter
Sound clips from OX2K operation "off the air":
http://hjem.get2net.dk/oz1pif/OX2K-sound.htm
********** OZ1PIF **************
email: oz1pif(no-spam-filler)@get2net.dk
http://hjem.get2net.dk/oz1pif
Shack Ph. +45 4619 3208
Snailmail:
Peter Frenning
Ternevej 23
DK-4130 Viby Sj.
Denmark
***********************************
----- Original Message -----
From: "Glenn McNeil" <vk4tzl@bigpond.com>
To: <amps@contesting.com>
Sent: Thursday, May 17, 2001 4:45 AM
Subject: [AMPS] Voltage Doublers...thanks for the info.
>
> To Rich, Dick, Steve and Ian...and any others I may have missed...
>
> Thanks for all your input. Certainly there is more to FWD than I thought
about.
>
> Further delving into the transformers background at this end has come up
with the following :
>
> Primary Resistance is 1.4 ohms
> Secondary Resistance is 12 ohms
> I intend to use 5 x 190uf 400v caps in each leg with 1N5408 diodes.
> I'm only trying to run a single 4CX250R
> After sifting through lots of paper, I have discovered that the no load
secondary voltage is 830 vac, up from my
> approximate guess of 750 vac.
> The transformer will only be supplying EHT...no other voltages.
>
> I think Steve suggested a lash up first....my metalwork at this stage will
allow this.
>
> I have a copy of a Yaesu power supply in one of their linears...not sure
which one, as I only have the relevant bit
> after the transformer, which is very similar to what I have...850v with
100uf 500v caps....albeit I dont know what the
> transformer specs are.
>
> Anyway, now how to figure out how to load the lash up to see what I
achieve.
>
> 73
>
> Glenn
> VK4TZL
>
>
>
>
> --
> FAQ on WWW: http://www.contesting.com/FAQ/amps
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
>
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|