My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.
Becourse the price was so good i took the challenge to build a 88-108
Mhz final from it.
After some experimenting i found out that the anode resonator a a bit
of a problem course of the high cappacity of the tube.
I try to do it with a double output coil (together Almost a half wave)
wich you see in manny designs for 144 Mhz amateur amps using for
example the russian tube GU84.
This works but it has a terrible efficiency,about 25%.
I hope that somebody can give me some Info about making a good and
high efficiend tank with this kind of tube.


Greetings.....Onno

look at (and copy) the final circuit from a BE-5A (broadcast electronics) FM
transmitter.It's very simple and very stable too. It likes about 200 watts
of drive from a IPA. Will run nicely with 5000 volts at about 1 amp on the
plate. In the BE transmitter the tube sits in a cavity, with the plate being
slide tuned. A coupling loop sits close to the tube....Eddie

"Onno de Vries." wrote in message
om...
My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.
Becourse the price was so good i took the challenge to build a 88-108
Mhz final from it.
After some experimenting i found out that the anode resonator a a bit
of a problem course of the high cappacity of the tube.
I try to do it with a double output coil (together Almost a half wave)
wich you see in manny designs for 144 Mhz amateur amps using for
example the russian tube GU84.
This works but it has a terrible efficiency,about 25%.
I hope that somebody can give me some Info about making a good and
high efficiend tank with this kind of tube.


Greetings.....Onno

look at (and copy) the final circuit from a BE-5A (broadcast electronics) FM
transmitter.It's very simple and very stable too. It likes about 200 watts
of drive from a IPA. Will run nicely with 5000 volts at about 1 amp on the
plate. In the BE transmitter the tube sits in a cavity, with the plate being
slide tuned. A coupling loop sits close to the tube....Eddie

"Onno de Vries." wrote in message
om...
My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.
Becourse the price was so good i took the challenge to build a 88-108
Mhz final from it.
After some experimenting i found out that the anode resonator a a bit
of a problem course of the high cappacity of the tube.
I try to do it with a double output coil (together Almost a half wave)
wich you see in manny designs for 144 Mhz amateur amps using for
example the russian tube GU84.
This works but it has a terrible efficiency,about 25%.
I hope that somebody can give me some Info about making a good and
high efficiend tank with this kind of tube.


Greetings.....Onno

On Fri, 06 Feb 2004 06:23:16 GMT, "Eddie Haskel"
wrote:

look at (and copy) the final circuit from a BE-5A (broadcast electronics) FM
transmitter.It's very simple and very stable too. It likes about 200 watts
of drive from a IPA. Will run nicely with 5000 volts at about 1 amp on the
plate. In the BE transmitter the tube sits in a cavity, with the plate being
slide tuned. A coupling loop sits close to the tube....Eddie

"Onno de Vries." wrote in message
. com...
My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.

SNIP


Greetings.....Onno


the 4CX5000A takes 10 Volts at 75 Amps, if I remember correctly.
Dave F.

On Fri, 06 Feb 2004 06:23:16 GMT, "Eddie Haskel"
wrote:

look at (and copy) the final circuit from a BE-5A (broadcast electronics) FM
transmitter.It's very simple and very stable too. It likes about 200 watts
of drive from a IPA. Will run nicely with 5000 volts at about 1 amp on the
plate. In the BE transmitter the tube sits in a cavity, with the plate being
slide tuned. A coupling loop sits close to the tube....Eddie

"Onno de Vries." wrote in message
. com...
My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.

SNIP


Greetings.....Onno


the 4CX5000A takes 10 Volts at 75 Amps, if I remember correctly.
Dave F.

On Fri, 06 Feb 2004 01:23:53 -0700, Dave Foreman wrote:

On Fri, 06 Feb 2004 06:23:16 GMT, "Eddie Haskel"
wrote:

look at (and copy) the final circuit from a BE-5A (broadcast electronics) FM
transmitter.It's very simple and very stable too. It likes about 200 watts
of drive from a IPA. Will run nicely with 5000 volts at about 1 amp on the
plate. In the BE transmitter the tube sits in a cavity, with the plate being
slide tuned. A coupling loop sits close to the tube....Eddie

"Onno de Vries." wrote in message
.com...
My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.

SNIP


Greetings.....Onno


the 4CX5000A takes 10 Volts at 75 Amps, if I remember correctly.
Dave F.

Meant to say on the filiment, I had one at one time and
mostly used as a paper weight.
Dave F.

On Fri, 06 Feb 2004 01:23:53 -0700, Dave Foreman wrote:

On Fri, 06 Feb 2004 06:23:16 GMT, "Eddie Haskel"
wrote:

look at (and copy) the final circuit from a BE-5A (broadcast electronics) FM
transmitter.It's very simple and very stable too. It likes about 200 watts
of drive from a IPA. Will run nicely with 5000 volts at about 1 amp on the
plate. In the BE transmitter the tube sits in a cavity, with the plate being
slide tuned. A coupling loop sits close to the tube....Eddie

"Onno de Vries." wrote in message
.com...
My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.

SNIP


Greetings.....Onno


the 4CX5000A takes 10 Volts at 75 Amps, if I remember correctly.
Dave F.

Meant to say on the filiment, I had one at one time and
mostly used as a paper weight.
Dave F.

Dave Foreman wrote in message . ..
On Fri, 06 Feb 2004 01:23:53 -0700, Dave Foreman wrote:

On Fri, 06 Feb 2004 06:23:16 GMT, "Eddie Haskel"
wrote:

look at (and copy) the final circuit from a BE-5A (broadcast electronics) FM
transmitter.It's very simple and very stable too. It likes about 200 watts
of drive from a IPA. Will run nicely with 5000 volts at about 1 amp on the
plate. In the BE transmitter the tube sits in a cavity, with the plate being
slide tuned. A coupling loop sits close to the tube....Eddie

"Onno de Vries." wrote in message
.com...
My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.

SNIP


Greetings.....Onno


the 4CX5000A takes 10 Volts at 75 Amps, if I remember correctly.
Dave F.

Meant to say on the filiment, I had one at one time and
mostly used as a paper weight.
Dave F.

Hallo Eddy. Thank's for responding.
I allready did some seaching for this BE-5A transmitter and i found it
manny time's. The onely problem is that photo's,schematic's or
manuals are not there.
Atleast i cannot find them. I had some more reactions on my call in
the broadcast group. The collins 830F and the harris FM-25K are alsow
transmitters with the 4CX in the final but here it's the same. I
cannot find anny photo's or manuals. I thought (when i bought this
tube)it would be easy to get some info about it becourse it it a
,,famous,,tube.

Well i wil keep on seaching........buy the way,if You know where i can
find what i need,please let me know.

Regards. Onno.

Dave Foreman wrote in message . ..
On Fri, 06 Feb 2004 01:23:53 -0700, Dave Foreman wrote:

On Fri, 06 Feb 2004 06:23:16 GMT, "Eddie Haskel"
wrote:

look at (and copy) the final circuit from a BE-5A (broadcast electronics) FM
transmitter.It's very simple and very stable too. It likes about 200 watts
of drive from a IPA. Will run nicely with 5000 volts at about 1 amp on the
plate. In the BE transmitter the tube sits in a cavity, with the plate being
slide tuned. A coupling loop sits close to the tube....Eddie

"Onno de Vries." wrote in message
.com...
My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.

SNIP


Greetings.....Onno


the 4CX5000A takes 10 Volts at 75 Amps, if I remember correctly.
Dave F.

Meant to say on the filiment, I had one at one time and
mostly used as a paper weight.
Dave F.

Hallo Eddy. Thank's for responding.
I allready did some seaching for this BE-5A transmitter and i found it
manny time's. The onely problem is that photo's,schematic's or
manuals are not there.
Atleast i cannot find them. I had some more reactions on my call in
the broadcast group. The collins 830F and the harris FM-25K are alsow
transmitters with the 4CX in the final but here it's the same. I
cannot find anny photo's or manuals. I thought (when i bought this
tube)it would be easy to get some info about it becourse it it a
,,famous,,tube.

Well i wil keep on seaching........buy the way,if You know where i can
find what i need,please let me know.

Regards. Onno.

Hallo Eddy. Thanks for responding. I did some seaching and i
can find this BE-5A manny time's but i cannot find photo's, schematics
,manuals wich can explane me a bit more in detail so i can build the
thing.
This time better than before,This double resonator.

If You know where i can find what i need please let me know.

Allready thank's Onno.


Dave Foreman wrote in message . ..
On Fri, 06 Feb 2004 01:23:53 -0700, Dave Foreman wrote:

On Fri, 06 Feb 2004 06:23:16 GMT, "Eddie Haskel"
wrote:

look at (and copy) the final circuit from a BE-5A (broadcast electronics) FM
transmitter.It's very simple and very stable too. It likes about 200 watts
of drive from a IPA. Will run nicely with 5000 volts at about 1 amp on the
plate. In the BE transmitter the tube sits in a cavity, with the plate being
slide tuned. A coupling loop sits close to the tube....Eddie

"Onno de Vries." wrote in message
.com...
My name is Onno de Vries and i'm living in the Netherland and building
big amps is my hobby.
I just bought a 4CX 5000A on a radio market here for a good price (180
Euro) including socket.

SNIP


Greetings.....Onno


the 4CX5000A takes 10 Volts at 75 Amps, if I remember correctly.
Dave F.

Meant to say on the filiment, I had one at one time and
mostly used as a paper weight.
Dave F.