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uBitX PA Drivers

Mike
 

I presume the driver pairs Q92,Q93/Q96,Q97 are in parallel to increase current handling . . . any recommendations to replace with just a single pair, something rated a little heftier?

M Garza <mgarza896@...>
 

If you have some 2SC1973s lying around, you could sub those in.  They would produce about 2 watts or so in a push-pull circuit.  They are rated for 1 watt each.

Remember, this was made to be something easily repairable.  I don't think 2N3904s will be going obsolete anytime soon.

Marco - KG5PRT 



On Jan 22, 2018 10:44 PM, "Mike" <msmith@...> wrote:
I presume the driver pairs Q92,Q93/Q96,Q97 are in parallel to increase current handling . . . any recommendations to replace with just a single pair, something rated a little heftier?

Mike
 

On Mon, Jan 22, 2018 at 09:00 pm, M Garza wrote:
2SC1973

Mike
 

Thanks . . . for the value of single emitter resistor (to replace the 22ohm pairs), would I use 11 ohm?

K9HZ <bill@...>
 

Those are excellent low power RF amplifiers… will work above the 432 band…

 

 

Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com

Like us on Facebook! facebook icon

 

 

email:  bill@...

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Mike
Sent: Tuesday, January 23, 2018 3:56 AM
To: BITX20@groups.io
Subject: Re: [BITX20] uBitX PA Drivers

 

On Mon, Jan 22, 2018 at 09:00 pm, M Garza wrote:

2SC1973

M Garza <mgarza896@...>
 

Looking at different schematics, the resistor is usually about 12 ohms.  I would think 11 or even 10 ohms would be fine.  I have attached the part data sheet.  I have not tried this, so YMMV.  It was just an idea.  If you have any old 10/11 meter SSB radios, you might be able to salvage a couple to try with.

Let us know, if you do try this.

Marco - KG5PRT 

On Jan 23, 2018 7:17 AM, "K9HZ" <bill@...> wrote:

Those are excellent low power RF amplifiers… will work above the 432 band…

 

 

Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com

Like us on Facebook! facebook icon

 

 

email:  bill@...

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Mike
Sent: Tuesday, January 23, 2018 3:56 AM
To: BITX20@groups.io
Subject: Re: [BITX20] uBitX PA Drivers

 

On Mon, Jan 22, 2018 at 09:00 pm, M Garza wrote:

2SC1973