Gonset GSB-201, "Frame-Up" restoration --- A SAGA

[GlocknSpiel]

Progress is slowing down as Summer sets in and I'm overdue for an update. Even though there IS a/c , it's still too hot out there, so I really haven't done much this entire month. Anyhow;

I got the input tuner installed, and it works great!
The soft-start module is in-place, and the discharge tubes and new .0047Uf input cap are installed on the tube filament buss.
The OG real estate hogging perf-board circuit had to be moved forward 1" in order to provide clearance for the two fuse holders on the back.
All coaxes are replaced.
I had issues with the homebrew 12/24VDC, tuner feeding, bias-providing power supply's PCB mounting holes not wanting to be drilled-out wide enough (they all broke-out), so I have to re-mount everything on a new PCB, --- or find a store-bought module small enough for the only space left for one...... So more later on that.
EDIT: The pencil scribble on the tube sub-chassis is from previous owner(s).

 

[SuperLid]

Gonset GSB201 Moderniziation.
YEARS ago, (1995 I think), I picked this old girl up at a local tailgate, and it came with the original manual. I traded an old Kenwood TS-7500 2 meter rig for it. As you can see in the pics, this amp was very rough, but I'm just attracted to 'old iron'. And at 81Lbs, this sure fits that bill just fine. I brought her home, hoisted it up on my heaviest bench, and brought it up on the variac. I recall that I got around 400W full-drive from it before backing away from it. While staring certain death in the face the whole time, I didn't want to "push any envelopes"... I was SO afraid of it after a day's worth of tinkering with it, that I built a sturdy dolly for it, and wheeled it under the bench, never to see daylight again.... Until today.

I'm sorry, but this is truly going to be a "saga", y'all., to be updated as I make any progress on it. But it's a flat mess. I plan to not only get her chooching again, but I intend to modernize the circuit as best I can as I go. I'm documenting this process here because I'm sure that if I'M willing to do this, there are other radio heads with these sweet old boatanchors under their bench. So let's do this!
I just hope my skill level is up to the task!

Here it is, in all of it's present OEM glory. I know, it's fugly. Outside of a new paint job at some point during this project, it'll likely remain fairly fugly. But I see an 81 pound "diamond in a cesspool".

I am enjoying your saga! I almost bought one of these once years ago, but the lack of a 220(240)VAC tap was the dealbreaker for me. You are doing a very nice job on this. Good luck!

 

[mrniles]

Hi. I too have a GSB-201 that I plan to restore. Can you tell me which soft start unit you are using and also what is the white substance on the new filter caps?

Thanks

Ivan

 

[sgarbo]

I also have a gonset, I would like to modify the tuning circuit, what parts did you use. Also do you have more updates to this project ?

 

[GlocknSpiel]

Hi. I too have a GSB-201 that I plan to restore. Can you tell me which soft start unit you are using and also what is the white substance on the new filter caps?

Thanks

Ivan

Ivan, The soft Start is a ready-made module available on Ebay (here).

EDIT: I just checked, and that SS module I linked to here is DIFFERENT than the one I'm using (purchased in 2024 and, albeit, from the same dealer). When I just went back to check for it's part number, this one popped up. No worries, as either will fit in the same "real estate footprint" of the chassis, if the OG is no longer available.

I'll have to look again, but I think the "white substance" you're referring to is just white RTV that I used to cement the OG (but cut-down) filter capacitor jackets over the new caps. I did that to try to "maintain stock appearances", but given the "hack job" to get the input tuner installed and other "body work", it was sort of a silly effort to 'keep it looking original'...... Totally cosmetic. EDIT: Confirming, yes it's just 'glue'.

My apologies to ALL for dropping the ball on that thing. It's even STILL on my rolling bench. At 81 lbs, I think it owns that bench top now. I doubt I'll ever finish it.
I had eye surgery which sort of led to an end to any progress on that amp among other things. It's a shame too, as there isn't much left to do. The bias, relay keying circuits, power cord install, neutralization and final assembly are all that remain.

 

[GlocknSpiel]

I also have a gonset, I would like to modify the tuning circuit, what parts did you use. Also do you have more updates to this project ?

Hi, Steven. The input tuning is automatic as opposed to the standard manual bandswitching arrangement. And it's provided by a cheap, over-the-counter automatic tuner called an ATU-100, designed by N7DDC and is "open source". These can be purchased pre-assembled, or in kit form. It was a little tight getting it in there, and a Dremmel tool was involved --- but it really worked out VERY well.

 

[GlocknSpiel]

Is there anyone who would like to pick up where i left off on this amp? 100% FREE, but at 81Lbs and "some assembly required", I really don't think it's a candidate for shipping anywhere --- Even with the new 811's included. I live in SW Florida, so if anyone wants a overweight, half-finished bench queen, come & get her.
Drop me a PM.