[NLRS] Looking for 70cm 4CX250B amp design....

[Ronald Bergantzel]

Hello All !! I got to share something here - Why use the 4CX250's ?? Just spend the $150 for a GS35 and have a tube amplifier that is considerable more robust ( read reliable and forgiving ) , has the ability to run almost any output you would ever want and MUCH simpler to construct  (see - QRO via Russia website ) .You do not need a seperate grid and screen supply....  Just for instance , I fired my GS35 up last weekend and had HEAVY Frost on the 2M12 antenna  - had 255 watts reflected and 1.5 kw out and had NO damage - I even used several short transmissions to thaw - out the driven element !! Also I never have to worry about over - driving it . In closing , with proper power supply design the GS35 has NO problems running the digital modes at 100% duty cycle at 1.5 kw output on multiple amplifiers that I have built / run  . Just a thought involving real world past experiences ...... 73s and GL on the amp Project !! Ron KA0RYT 
P.S - Projects that I am currently working on - Modifying several ex-broadcast Thompson  TH347 cavitys for legal limit on 1296 and 432 along with very low noise preamps for 1296 using some of the newest devices (can we say tiny SMT ? ) ....RB  
--------------------------------------------
On Thu, 1/9/14, Matt Burt <kf0q at hbci.com> wrote:

 Subject: Re: [NLRS] Looking for 70cm 4CX250B amp design....
 To: "Floyd Patten" <bud.patten at frontiernet.net>
 Cc: nlrs at mailman.qth.net
 Date: Thursday, January 9, 2014, 4:00 PM
 
 
 
 Hello Bud,
 
 Not exactly what you are looking for but really close and
 some good  
 reading found here:
 
 http://www.qsl.net/w8ujx/432amp.pdf
 
 Good luck,
 
 Matt - KF0Q
 
 ----- Message from geraldj at netins.net
 ---------
 Date: Thu, 09 Jan 2014 15:39:43 -0600
 From: "Dr. Gerald N. Johnson" <geraldj at netins.net>
 Reply-To: geraldj at netins.net
 Subject: Re: [NLRS] Looking for 70cm 4CX250B amp design....
 To: nlrs at mailman.qth.net
 
 >
 >
 > I should have the print magazine somewhere, and I know
 I have it on
 
 > DVD in the form of a pdf file per issue and the scans
 are sharp.
 The
 > whole issue is nearly 18 mb, way to big for an e-mail
 attachment.
 IF
 > Donn's offer doesn't work I can post it temporarily on
 an FTP
 server.
 >
 > The output tank on that design is dual band but I think
 it can
 easily
 > be trimmed to be single band 432 only. It will probably
 need a new  
 > grid circuit for 432. I'm sure there have been a few of
 those  
 > published.
 >
 > 73, Jerry, K0CQ
 >
 > On 1/9/2014 2:27 PM, Floyd Patten wrote:
 >>
 >>
 >> Do any of you have a copy of the Feb '70 issue of
 HR with the 'RIW
 
 >> tripler/amplifier design? I'm looking for a
 stripline 70 cm amp
 to
 >> build.
 >>
 >> Tnx,
 >> Bud
 >> w0lcp
 >>
 ______________________________________________________________
 >> NLRS mailing list
 >> Home: http://mailman.qth.net/mailman/listinfo/nlrs
 >> Help: http://mailman.qth.net/mmfaq.htm
 >> Post: mailto:NLRS at mailman.qth.net
 >>
 >> This list hosted by: http://www.qsl.net
 >> Please help support this email list:
 http://www.qsl.net/donate.html
 >>
 >>
 >
 >
 ______________________________________________________________
 > NLRS mailing list
 > Home: http://mailman.qth.net/mailman/listinfo/nlrs
 > Help: http://mailman.qth.net/mmfaq.htm
 > Post: mailto:NLRS at mailman.qth.net
 >
 > This list hosted by: http://www.qsl.net
 > Please help support this email list: http://www.qsl.net/donate.html
 >
 >
 
 ----- End message from geraldj at netins.net
 -----
 
 
 
 ______________________________________________________________
 NLRS mailing list
 Home: http://mailman.qth.net/mailman/listinfo/nlrs
 Help: http://mailman.qth.net/mmfaq.htm
 Post: mailto:NLRS at mailman.qth.net
 
 This list hosted by: http://www.qsl.net
 Please help support this email list: http://www.qsl.net/donate.html