[NJARC] Knight KX-60 Amplifier

[Mike Feher]

Al -

Great, now I do not have to go down in the basement or mail a package, HI.
As I mentioned earlier, this is a simple C multiplier. An hfe of 10 is
adequate, but, I even wonder if you can find transistors that low. And, in
this case, you do not really need them anyway if you could increase the C.
Typical germanium current gains were less than that of silicon, and I
measured two of the 2N4398s here and they were both close to 200. I am sure
whatever PNP germanium/silicon you bring will be just fine for Chuck. 73 -
Mike 

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 


-----Original Message-----
From: Al Klase [mailto:ark at ar88.net] 
Sent: Friday, June 10, 2016 1:34 PM
To: Mike Feher; 'Chuck'; njarc at mailman.qth.net
Subject: Re: [NJARC] Knight KX-60 Amplifier

Chuck,

Mike's analysis has been spot on.  In this particular circuit, silicon
should work just fine, that's not always the case.

In the mean time I dug through my Germanium power box, and will bring some
PNP TO-3 along to the meeting.

Mike, can you take a SWAG at the required HFE (gain).  I'm thing 10 would be
sufficient.

Al

Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/

On 6/10/2016 12:35 PM, Mike Feher wrote:
> Chuck -
>
> Even without going downstairs, which I try to avoid nowadays, I found 
> some 2N4398s by Motorola that are NOS. These are TO-3 PNPs but 
> silicon. I am sure they will work just fine in that circuit. You can 
> pick them up, or, I can mail them to you. Here is the data sheet. 73 - 
> Mike
>
> http://www.nteinc.com/specs/original/2N4398_99.pdf
>
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell, NJ, 07731
> 732-886-5960
>
>
> -----Original Message-----
> From: Chuck [mailto:cpaci1 at verizon.net]
> Sent: Friday, June 10, 2016 11:09 AM
> To: Mike Feher; 'Al Klase'; njarc at mailman.qth.net
> Subject: Re: [NJARC] Knight KX-60 Amplifier
>
> Thank you Mike.
> You have been a great help!
> And -- I would be more than happy to pay for those transistors.
> See you tonight at the meeting.
> Thanks again!!!!!!!
> Chuck
>
> -----Original Message-----
> From: Mike Feher
> Sent: Friday, June 10, 2016 10:57 AM
> To: 'Chuck' ; 'Al Klase' ; njarc at mailman.qth.net
> Subject: RE: [NJARC] Knight KX-60 Amplifier
>
> If I find a couple you can have them. I just have to go downstairs and 
> check, but, I know I have them. They are really not that critical as 
> the voltages on all three junctions is essentially the same. Your only 
> real criteria is that they be PNP in a TO-3 style package. Even NPNs 
> would work, but would require some circuit topology of the PS to 
> change. Even silicon will work, giving you a few tenths of a volt less 
> out. Will let you know as I have thousands. 73 - Mike
>
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell, NJ, 07731
> 732-886-5960
>
>
> -----Original Message-----
> From: Chuck [mailto:cpaci1 at verizon.net]
> Sent: Friday, June 10, 2016 10:09 AM
> To: Mike Feher; 'Al Klase'; njarc at mailman.qth.net
> Subject: Re: [NJARC] Knight KX-60 Amplifier
>
> Hi Mike,
> That sounds very plausible.
> My experience with solid state is fairly limited and this power supply 
> circuit design is new to me.
> If you do find a couple transistors that will work, I will buy them 
> from you.
>
> Thanks Mike...
> Chuck
>
> -----Original Message-----
> From: Mike Feher
> Sent: Friday, June 10, 2016 7:16 AM
> To: 'Chuck' ; 'Al Klase' ; njarc at mailman.qth.net
> Subject: RE: [NJARC] Knight KX-60 Amplifier
>
> Chuck -
>
> I believe on this case the transistors are acting as C multipliers 
> using the Miller effect. The diodes are doing the rectification. I 
> have lots of PNP power Ge transistors. 73 - Mike
>
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell, NJ, 07731
> 732-886-5960
>
> -----Original Message-----
> From: NJARC [mailto:njarc-bounces at mailman.qth.net] On Behalf Of Chuck
> Sent: Friday, June 10, 2016 4:40 AM
> To: Al Klase; njarc at mailman.qth.net
> Subject: Re: [NJARC] Knight KX-60 Amplifier
>
> Just remember
> Reply = Poster
> Reply All = Everyone
>
> _________________________________________________________
>