[NJARC] Knight KX-60 Amplifier
Rich
rjlfirst at msn.com
Sat Jun 11 08:42:01 EDT 2016
Mike,
Right on. I didn't see the schematic. For some reason I thought that you
guys were referring to an early transistorized car radio. I may have mixed
up a couple of emails. But I would be happy to take a look at the schematic
if things don't work out for you.
Rich L.
--------------------------------------------------
From: "Mike Feher" <n4fs at eozinc.com>
Sent: Friday, June 10, 2016 11:48 PM
To: "'Chuck'" <cpaci1 at verizon.net>; "'Rich'" <rjlfirst at msn.com>;
<njarc at mailman.qth.net>; "'Al Klase'" <ark at ar88.net>
Subject: RE: [NJARC] Knight KX-60 Amplifier
> I do not believe that Rich read the earlier emails and saw the schematic
> of
> where these are used. So, I did not comment on his post. Let us know
> Chuck.
> 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 11:45 PM
> To: Rich; Mike Feher; njarc at mailman.qth.net; Al Klase
> Subject: Re: [NJARC] Knight KX-60 Amplifier
>
> Hi Rich,
> I think I got the right type from Al tonight at the meeting.
> I'm going to give that a try tomorrow.
> I'll let everyone know if it works...
>
> Thanks for the heads-up Rich!
>
> Chuck
>
>
> -----Original Message-----
> From: Rich
> Sent: Friday, June 10, 2016 9:04 PM
> To: Mike Feher ; 'Chuck' ; njarc at mailman.qth.net ; Al Klase
> Subject: Re: [NJARC] Knight KX-60 Amplifier
>
> Hi guys,
>
> I use to repair those old transistor car radios and just wanted to say
> that
> as you know most used Ge PNP power transistors. Substituting a silicon PNP
> will usually result in cross-over distortion due to the difference in the
> base-emitter bias voltage. Give it a try, it will not cause any damage,
> just a good possibility of distortion.
>
> Good Luck with it,
> Rich L.
>
> --------------------------------------------------
> From: "Al Klase" <ark at ar88.net>
> Sent: Friday, June 10, 2016 1:34 PM
> To: "Mike Feher" <n4fs at eozinc.com>; "'Chuck'" <cpaci1 at verizon.net>;
> <njarc at mailman.qth.net>
> Subject: Re: [NJARC] Knight KX-60 Amplifier
>
>> Just remember
>> Reply = Poster
>> Reply All = Everyone
>>
>> _________________________________________________________
>> 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
>>>
>>> _________________________________________________________
>>>
>>
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