----- Original Message -----
Sent: Thursday, May 31, 2012 5:09
PM
Subject: LF: Re: Re: Re: 475 kc Exiter
/JUMA
Mal,
in which sense do you think is your
mail helpful for Uwe or other list members?
Instead of ad nauseum repeated emails
from you bragging with your home brewing
and CW skills,your
antennas,etc.we would like to see mails from you containing
some possibly useful information for the list
members
73
Clemens
DL4RAJ
----- Original Message -----
Sent: Thursday, May 31, 2012 6:08
PM
Subject: LF: Re: Re: 475 kc Exiter
/JUMA
Uwe
I could build the same specification 60w rig for NO
cost out of my junk box hi. The rig seems expensive for a kit and only 60
watts
The Ropex 130 w rig for 136 Khz was less
than £200 new and already built, even that was expensive. I built a 1Kw
rig for almost nothing out of my junk box and still have after many
years.
I also have a couple of MF marine transmitters
suitable for 500 lying in my garage !!
de mal/g3kev
----- Original Message -----
Sent: Thursday, May 31, 2012 3:10
PM
Subject: LF: Re: 475 kc Exiter
/JUMA
Hi,
here is the bill for my new JUMA TX500
Subtotal: 299.00€
Postage &
Packaging: 26.00€
Tax: 68.77€
Grand Total: 393.77€
I´s by the way the 3rd kit I am building
( all bevore where built for others ..) but thats for my self
..
Uwe DK1KQ
Sent: Thursday, May 31, 2012 1:43 PM
Subject: Re: LF: 475 kc Exiter /JUMA
Hi
Clemens,
Oh, OK. But anyway it was a very good hint to mention the
JUMA 500 TX since it leads me to the CMCD design and this paper which
nicely describes the problem of the VMCD desgin which i am trying in my
first tests.
The output C of the FETs is the problem. Since i want to
have a relatively high power (100W) at 12V DC, the primary impedance is
very low. So i have to use FETs with a very low on-resistance, ideally as
low as possible of course. To find them is no problem (e.g.
IRFP4368),
but the output C is much to high then. I tried a IRZF48N (2 of them of
course) as a compromise between RDSon and Cout but am just getting 60%
efficiency at 70W in the first attempt. That's not acceptable for a /p PA
that has to stay compact, i.e. without a big heat sink and/or a
fan...
The basics are well explained in this paper, makes fun to
read :-)
73, Stefan/DK7FC
Am 31.05.2012 13:08, schrieb
Clemens Paul:
It costs 300 Euro which is not to
much.
Unfortunately you have to add 23%VAT tax
within EU and shipping costs
which I estimate to 30-40 Euro.
So
we end up somewhere around 400 Euro.
Interesting kit,though.
73
Clemens
DL4RAJ
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