[Boatanchors] AM 100 Watt Transmitter Designs

Robert Groh rgroh at swbell.net
Mon Jan 16 13:12:09 EST 2012


Loved your outline. Makes me want to do the same - in fact, I will keep it 
around just in case I ever have some spare time.  That is pretty much what I did 
back in the early 80's - purchased a VFO module, build up a 6146 final and 
appropriate PS. Never finished it and have since sold the VFO and broke down the 
rest.  But I really like the idea of a 'modular' approach.  

One thought that occurred to me is that using one of the Heathkit HP-23() line 
of power supply's might a nice part of such a line up. One could buy one of the 
conversion kits to upgrade the PS with a new PC Bd, capacitors, etc. That alone 
would give someone a great start at getting into building something.

Bob Groh, WA2CKY

From: Wilson Lamb <infomet at embarqmail.com>
To: bcarling at cfl.rr.com; FLBOATANCHORS at yahoogroups.com; 
tetrode at googlegroups.com; hamradiohomebrew at yahoogroups.com; 
boatanchors at puck.nether.net
Cc: burnsguitar at yahoo.com
Sent: Sun, January 15, 2012 6:40:21 PM
Subject: Re: [Boatanchors] AM 100 Watt Transmitter Designs

Avoid sweep tubes.
Start with ONE 807, 1625, or 6146.  All are cheap and available.  Find out the 
output level of your VFO and choose a tube to follow it.  It's likely that stage 
will drive a single amp tube.
Avoid two tube finals to start.  They are harder to build, harder to debug, less 
stable, and not worth the trouble at your stage.  Anyone you can work with 100W 
will hear you at 50W!
Build the mod and RF sections separate, so you can use them with different 
partners.  A good mod will last forever, with many RF sections.
If you don't mind being a little retro, use plugin coils.  Bandswitches and coil 
banks are tedious and winding coils is fun.
A pair of 6L6s will modulate up to about 75W of RF and they are easy to handle.  
A pair of 6146s is a great mod, but will require careful gain control with  A 
50w RF section.
You'll get lots more enjoyment from a smallish simple rig that works and gets 
you on the air sooner than something more ambitious.
Spend a few weeks studying all the books you can find, especially Handbook and 
QST articles AND looking for parts.  Let the parts help determine the design.  
The mod xfmr will likely be the most elusive part, but maybe the community will 
come through for you.
Go to hamfests and look for chassis, panels, meters, xfmrs, etc.  Once people 
see you working, many will help!
----- Original Message ----- From: "Bry Carling" <bcarling at cfl.rr.com>
To: <FLBOATANCHORS at yahoogroups.com>; <tetrode at googlegroups.com>; 
<hamradiohomebrew at yahoogroups.com>; <boatanchors at puck.nether.net>
Cc: <burnsguitar at yahoo.com>
Sent: Sunday, January 15, 2012 7:38 AM
Subject: [Boatanchors] AM 100 Watt Transmitter Designs

> Can anyone help this fellow?
> He is looking for an AM transmitter article and would like to do some 
>homebrewing after a
> FEW years absence form ham radio!
> He may not be reading this group, so be sure to do a "REPLY TO ALL" here to 
>help him...
> FWD from another group:
>    Posted by: Brian Burns
> burnsguitar at yahoo.com
>    Date: Sat Jan 14, 2012 3:07 pm ((PST))
> Hello All,
> I'm getting back into ham radio after a mere 53 years doing other
> things!
> Back in the day, I worked mostly CW, and want to do that again, but I'm
> really interested in AM. An old ham friend has equipped me with an SSB/CW
> transceiver, and I'm getting an HQ-145 to restore for AM reception.
> I'm looking for an article on building an all band AM tube transmitter
> that's good for about 100 watts, give or take. I'm concerned about parts
> availability, so any help in that direction would be greatly appreciated
> too. I'll be building a digital VFO kit, so this will be something of a
> hybrid rig. Here is the link to the kit:
> http://www.pongrance.com/super-dds.html
> Cheers,
> Brian Burns  Once and future K6UCD
> _______________________________________________
> Boatanchors mailing list
> Boatanchors at puck.nether.net
> https://puck.nether.net/mailman/listinfo/boatanchors 

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