Wanted: 3 sweep tube or larger mobile amp

[nomadradio]

I compare using sweep tubes for mobile RF power to mowing your lawn with a restored 1908 steam tractor.

Sure, you could given enough money. But more cost-effective alternatives have been commonplace for generations.

I like the Idea of a tube mobile

Maybe more like "in love with the idea...."?

Just remember. True love ain't never cheap.

Then again, I'd love to see someone with the engineering talent come up with a modern-day power-MOSFET way to run the HV step-up circuit. The germanium power transistors everyone used back then were failure-prone. As they become more obsolete and rare, the price for those parts has skyrocketed. Seems like some clever circuit with couple of high-current modern parts could be dropped in, using the original step-up transformer. A stable source of high voltage would improve the way the old boogers work.

Wont' see me develop it, though.

73

 

[nomadradio]

Whup! Can't edit a post in this section. I'll check the basement and see if I really did sell off all of the specimens we had saved. Tried to unload all of them on fleabay, but it's worth a look next time I visit the basement. Sure haven't tried to fix one in literally decades.

73

 

[jtrouter]

Whup! Can't edit a post in this section. I'll check the basement and see if I really did sell off all of the specimens we had saved. Tried to unload all of them on fleabay, but it's worth a look next time I visit the basement. Sure haven't tried to fix one in literally decades.

73

Well i love the old sweep tube amps, I collect them and s l o w l y repair them. My problem is after that i should sell them but for some reason they just end up on my shelves. It seems once they are cleaned up painted or whatever it takes to make them look and work good i just cant let them go? The worst part is i am always on the hunt for a good price on tubes. So anyone that have sweep tubes shoot me a line if you want to sell some a a good price.

 

[Enterprise312ok]

I Have found what I am looking for, I just need to make the $ happen before its sells. I lost a few days of work the last couple week because of slow material deliveries. Its new old stock

 

[Enterprise312ok]

Not trying to be an ass but why do you feel the need for an amp?

Just curious, what kind of station do you run. I have made contact with italy on a barefoot radio with a 1/4 wave antenna so I know you dont have to have an amp for dx. I am not one of the guys who stand In the road I like to call and then qso on a quieter channel. I dont overdrive my stuff. Just wanted to let you know I am not one of the loud mouth "amp champs"
I listen far more than I talk but when I key down I want to punch through.

 

[nomadradio]

Way cool! Haven't seen one of those in decades. I remember climbing inside the trunk of a customer's car back in the 80s to tune an amplifier like this. Heard the crowd yelling "Unkey it" When I lifted the trunk lid, his fiberglass antennas were smoking, and the shrink tubing was peeling off of them.

Watts is Watts. How you come up with them is your business.

Best of luck and 73!

 

[w9cll]

Long range mobile to base communications under heavy qrm, and shooting skip on busy channels, I also get up around 27.555 and talk international power sure helps when austrailia or brazil comes in.

Ahh... Okay have fun

 

[w9cll]

Just curious, what kind of station do you run. I have made contact with italy on a barefoot radio with a 1/4 wave antenna so I know you dont have to have an amp for dx. I am not one of the guys who stand In the road I like to call and then qso on a quieter channel. I dont overdrive my stuff. Just wanted to let you know I am not one of the loud mouth "amp champs"
I listen far more than I talk but when I key down I want to punch through.

run a home made fan dipole at 30 feet and a five band hex beam at 45 feet. When I ran HF in the car I used a High Serria screwdriver antenna. I have never needed an amp and I have worked Japan and Argentina mobile at 100 watts. I have worked almost every country in the world and I hope to get all of them sometime soon. I really don't believe in amps, I feel they are more trouble than what they provide. Even in my 11 meter days the only amp I ever had was a Sonar BR-21 which was only 50 watts.

 

[Enterprise312ok]

Not that it will bleed over, it's just the rough treatment that tubes have to endure.
I had a PAL 350 mdx with 8950 tubes in it in a old Datsun pickup one time and it ate tubes and fuses.
I would go off road bouncing around and stop and turn the amp on and it would blow the fuse.
Pull the tubes, and find one or more shorted.
That was not so bad when they were $12 bucks each at Thrifty but I would hate to do that when they are $60 bucks if you can even find them.
They have thin wires spot welded inside the tubes that do not play well with hard hits bouncing around in a pickup.
I guess if you only drive down nice smooth pavement it would be less hazardous.

Best of luck.

73
Jeff

Sometimes it takes a while, but wishes do come true.
I think I will try it with the m2057 tubes I have.

 

[BJ radionut]

2057's

What is a single tube rated for roughly. Someone brought over an amp that has 3 driving 8. I got it up and running. Not sure what the problem was really it works on low and hi. Low does about 500 pep. Hi does around 1400 top end. I'm sure that's more than what those tubes are rated for for...

www.worldwidedx.com

Having run a similar amp on 10 meters years ago mobile...
(1 driving 3 x 8950's) .... They don't travel well!
Vibration kills the tubes due to laying horizontal ...
Mine was BOLTED down to engine cover of my Ford E250 van...Talk like Son of a Bitch.....Would KILL the engine if keyed while idling or at stop light!
I had a dash mounted AMP Meter (0-35 amp) it drew 8 amps in stand-by...when keyed it PEGGED it a battery killer!!!!
OH Yes Squeals LOUD when keyed.

GL
All the Best
Gary

 

[Monk]

Just wanted to see what is out there. I really like the palomar 310m and the varmint xl 400 and xl 600. Wanting some old school heat to go behind my cobra 138xlr.
Dont really have the cash just yet but I Like something to work towards. I am in oklahoma but willing to pay shippimg if no local options.

HI,
I know this is an old post but you said you didn't have the cash when you posted so it has be over a year now. Maybe you have some cash now.
I do have a Palomar 310m in working condition, between 3 and 400 watts out, 100% tubes.
I also have a D&A MDA200 and a D&A Falcon 400.
If you are interested I can check the out again and give you some prices and weights for shipping info.

Monk

Woodland WA

 

[Enterprise312ok]

Well unfortunately I have found that I have a problem with mobile tube amps.
My mobile amp collection now includes a PAL mdx 350, Golden Falcon 150 , Maco Mini brute a Firebird 2bill of course I have a kriss 300m that is also a nice box.
Money is tight this time of year but I appreciate your reply.

 

[brandon7861]

Neighbor gave me a Varmint XL-450 last year, but it needs work and I'm not a tube guy. I have very little HV experience and don't want to risk it being I've never worked on one before. It probably needs tubes, which I was convinced could not be found. I have no idea whats actually wrong with it.

If I don't get around to fixing it this winter, I will likely post it for sale here along with a FL-2100B I don't use. I have a hard time letting go of things, but I'm slowly getting better at it.