Question before making amp purchase

[cjruger]

I found this tube amp on CL. It looks to me home made and well constructed, 3 tubes and 10-60 or 80 meters.
1st if it works on 10 meters will it work on 11?
Second the guy has no tuner to test it with, but said it powers up and had a ham friend go thru it and all looks to be well put together.
3rd what are the toggle switches for? Ssb?
He wants 275$ for it. I plan on getting my ham ticket soon and would like to start getting some gear together.Talk me out of it. Here is the add:

I have for sale a ham radio amplifier which I acquired some years ago from a old "elmer" that liked to build these in his leisure time. I have little to no knowledge about this or any other tube amps. I have given this to several knowledgeable hams for inspection and they all agree that everything appears to be as it should, and the manner of construction is outstanding. It does power up but has not been tested on the air. I haven't got the suitable setup to test it. Their inspections however were all consistent with its ability to function as it should in every respect. They believed it to be rated at 1000w. Please inspect the pictures closely and I'm sure you'll agree with its quality and attention to detail. I am pricing this less than I paid for it because I am no longer involving myself in ham radio for now.
I am asking $275 b/o
Thanks for looking

 

[wavrider]

I would need to see it work.
813 can be unstable above 14 mhz unless neutralized correctly.

This amp may have a GG design in which case you should be OK.

Looks like a tuned input is also in the amp.

Take a dummy load, watt meter, set of cables, and a transmitter to check it out.

 

[M0GVZ]

To expand on wavriders' post, yes it should but you'll need to retune the input for 10m otherwise your radio will just see high SWR.

 

[BJ radionut]

Also worth noting this amp would be a poor choice to be used for AM...I would not recommend that, but I don't recommend that on most amps unless they were over designed and constructed to be used on AM...ie... an amp designed for a KW output on SSB, should IMHO be operated at or below 40% duty cycle...KW(SSB)= 400 watts Peak (AM)...
Also that amp will require an interface and a rig with a keying circuit, it will not have an RF sensing circuit like most 11m type amps...The price is right thou if it works.

WAVRIDER, I am seeing to many transformers though to think this may be GG...(3) 813's GG would seem to be a little squirrely on 10m, but what the hell do I know!
I had a pair years ago in GG and they did not like 10m, but B & W made and excellent 813 amp that preformed fine on 10m with slightly less output than 80-20m???

However I must say I like the layout and construction that was done, be nice to have some documentation on it though.
All the Best
Gary

 

[cjruger]

To expand on wavriders' post, yes it should but you'll need to retune the input for 10m otherwise your radio will just see high SWR.

Ok, I am going to look at and probaly buy this thing tomorrow. I have questions that if anyone can answere i would greatly appreciate it.
-What is involved in retuning the input? I have never used a tube amp before and really dont know much about them.(I did read in the amp, sticky about tunning a tube amp, so if thats what is meant I kinda understand that)
-could you explain more what adding an interface and what is involved in adding a keying circuit? I dont know what that is.
-All I have right now is a 2950DX 10-12 meters( and a couple ssb cb's).as my base setup , Is this enough to drive this? I was told the guy that built it was driving it with 100watts from a EICO radio. I dont have a Ham rig. If it is not meant for AM maybe ill stay away from it? I use both AM and SSB usually in the 11 meter band,
Also what are the toggle switches for inside?
Any other input aprecciated as im going to check it out tomorrow morning. This stuff is new to me as im studying for taking my test to get my ticket. I only have this forum for questions, dont know anyone else to ask.

 

[wavrider]

BJ you are correct, I thought it was a choke in the back right side, that was after a shift at work.

Now that I have had some coffee it does indeed look like a TR.

Looks clean build, I would probably pick it up just to look at how it was built.

I always have been a sucker for old home brews. could be why there are so many roll around cabinets in the shack.

 

[cjruger]

I guess my only question is, what else will I need to use this with my 2950dx?