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THE AM BULLETIN BOARD => Technical Forum => Topic started by: WB2G on February 27, 2008, 11:54:30 AM



Title: Gonset GSB-101
Post by: WB2G on February 27, 2008, 11:54:30 AM
I was thinking of changing the 811A's in my Gonset GSB-101 to 572B'S,is there anything I should change ,or is this just a simple plug in swap.thanks.Joe WB2FQD


Title: Re: Gonset GSB-101
Post by: K3ZS on February 27, 2008, 12:39:16 PM
I have a GSB-101.    If you are not getting the full rated output power, I would just change to new 811's.    The 572s will cost much more, however they should last forever.   I don't think the power supply will be capable of providing much more current.    The 572's need a higher plate voltage to run more power than the GSB-101 provides.    I would change to high voltage stack rectifiers if you are still using 866's or 3B28's.



Title: Re: Gonset GSB-101
Post by: N3DRB The Derb on February 27, 2008, 06:10:38 PM
the only real benefit you'll see is not having to worry about the tubes. At that voltage level, 572B's r damn near indestructable. in my gsb 201, we went from bout 125 watts carrier to 225 making that swap, but the transformer/572B's in the 201 is capable of being loaded to 1000 ma for short times. the 101, I'm not so sure what the highest input rating is.

No one would ever notice the difference on air anyways. that first 10 to 12 db in your cb is where the action is. After that, you have to go to pretty large carriers sucking lotsa juice to make a difference.


Title: Re: Gonset GSB-101
Post by: WB2G on February 27, 2008, 07:16:47 PM
Indestructible sounds good,I'm using the 3B28's but I do have a few 7.5KV 1amp. diodes laying around.The transformer looks like its rated 3600VCT@500ma.CCSI think I'll leave the 3B28's in for the being and see how it works with my DX-60.Thanks.Joe,WB2FQD


Title: Re: Gonset GSB-101
Post by: N3DRB The Derb on February 27, 2008, 07:27:09 PM
yeah just put in the 572's and load it to whatever the manual says load the thing to with 811's.

The toobs are not the limiting factor, the rectifier stack / transformer is.


Title: Re: Gonset GSB-101
Post by: K3ZS on February 28, 2008, 10:37:58 AM
The GSB-101 is rated to run 275 ma input PA current.   It is rated at 175W AM output carrier.    You actually increase the loading until the output power drops to 175W in order to get the full PEP output.   Otherwise the audio will be crappy.



Title: Re: Gonset GSB-101
Post by: K3ZS on February 28, 2008, 10:40:22 AM
On the above, the 275 mA is the AM rating, CW it is 550 mA for full power.

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