Re: [AMRadio] info wanted on 4-400 linear amplifier
Ed, I always admire those about to undertake such a project. I don't have a circuit for you, but I will share a few ideas. If you do use grid driven, it will likely need to be class AB1 (zero drive power to tube, i.e, just voltage), or class Ab2 where the grid draws a little grid current on modulation peaks. In either case, 25 watts will be way too much. Given the above choices, I'd use Ab1, and a passive 50 ohm grid input resistor, and scale the drive just short of grid current. Still you will need a grid bias supply, and screen supply in addition to a plate supply. That is a lot of stuff, but hey, why not if you want to do it? Another approach, and I'm being a little simplistic here, is to think of a 4-400 in grounded grid as something similar to or about 4/5 a 3-500Z. A Heath SB-220 does legal limit AM with under 25 watts (carrier) of drive with two 3-500Z's in parallel G-G. No screen supply needed, and bias if necessary is easy with a power zener diode. So a 4-400 configured as a GG linear should be good for 150 to 200 watts am carrier output, and only need 10-15 watts carrier for drive. My figures are a SWAG, but I'd bet they are in the ballpark. Thanks for reading, Jim Candela WD5JKO --- [EMAIL PROTECTED] wrote: > I am planning to build a linear amp around a grid > driven 4-400 tube. Can > anyone suggest where I can find a suitable circuit > with component values. > I would like band-switching for 80, 40 and 20 > meters. I will be driving > it with a 25 watt carrier output rice box on AM. I > don't like the one in > the ARRL 1967 handbook because it requires you to > open the lid and > physically change taps on the coil and change tuning > capacitors. I don't > have any other older handbooks. Thank you. > > Ed K6UUZ > __ > AMRadio mailing list > Home: > http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
Re: [AMRadio] info wanted on 4-400 linear amplifier
Ed: the Johnson Thunderbolt is a AB2 amp that uses 4-400A's check out this amp i think you might like the layout it uses a roller inductor instead of a varicap. 73 Tony wa4jqs At 06:10 PM 8/2/2005 -0700, you wrote: I am planning to build a linear amp around a grid driven 4-400 tube. Can anyone suggest where I can find a suitable circuit with component values. I would like band-switching for 80, 40 and 20 meters. I will be driving it with a 25 watt carrier output rice box on AM. I don't like the one in the ARRL 1967 handbook because it requires you to open the lid and physically change taps on the coil and change tuning capacitors. I don't have any other older handbooks. Thank you. Ed K6UUZ __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net Anthony W. DePrato WA4JQS EXTRA - HEAVY CLASS Since 1962 South Sandwich Island Antarctic Dxpedition Group VP8BZL VP8SSI 3Y0PI V31SS ZD8JQS WA4JQS/4K1 WA4JQS/KC4 WA4JQS/ZS1 CQ DX HALL OF FAME # 35 A1-OP FISTS # 10573 AMI
Re: [AMRadio] Mike connectors needed
Hi Don, The best place I have found to buy the mic connectors you are needing is from The RF Connection (link below). They have the best prices around. Click on microphone connectors. 73, Mark http://users.erols.com/rfc/index1.htm Quoting "Rev. Don Sanders" <[EMAIL PROTECTED]>: > I am refurbishing several rigs and need microphone connectors as follows. > 2 each - Amphenol 2 pin chassis mount like on theHeath HW > series > 1 each - Amphenol 2 pin mating connector for above > that goes on the end of the mike cable. > 2 each - Amphenol or other 4 pin chassis mount >like on the TS520/530 series for mike >connector > 1 each - 8 pin chassis mount mike conn like on >the IC735 and similar rigs > If you have any or all of these please contact me > direct with quantity and price. [EMAIL PROTECTED] > Thanks. > Healthfully yours, > DON W4BWS > > Healthfully yours, > DON > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > >
[AMRadio] info wanted on 4-400 linear amplifier
I am planning to build a linear amp around a grid driven 4-400 tube. Can anyone suggest where I can find a suitable circuit with component values. I would like band-switching for 80, 40 and 20 meters. I will be driving it with a 25 watt carrier output rice box on AM. I don't like the one in the ARRL 1967 handbook because it requires you to open the lid and physically change taps on the coil and change tuning capacitors. I don't have any other older handbooks. Thank you. Ed K6UUZ
Re: [AMRadio] Mike connectors needed
The Amphenol connectors are available from Allied. They are now manufatured by Wire Pro. Bob Macklin K5MYJ Seattle, Wa.
[AMRadio] Mike connectors needed
I am refurbishing several rigs and need microphone connectors as follows. 2 each - Amphenol 2 pin chassis mount like on theHeath HW series 1 each - Amphenol 2 pin mating connector for above that goes on the end of the mike cable. 2 each - Amphenol or other 4 pin chassis mount like on the TS520/530 series for mike connector 1 each - 8 pin chassis mount mike conn like on the IC735 and similar rigs If you have any or all of these please contact me direct with quantity and price. [EMAIL PROTECTED] Thanks. Healthfully yours, DON W4BWS Healthfully yours, DON
