[ARC5] Transistorized ARC-5 Receiver

Mon Jan 2 14:05:29 EST 2017

Hi George,

I run my command receivers on batteries. They still have the original 
tubes and the 24-volt heater strings. I can operate them whether or not 
the electric utility can keep their wires in the air and I have a lot 
less conducted power line crap in my cans. However, I don't want to 
carry all that stuff over to the county park to operate there or to a 
hamfest for some show n tell. With solid state devices they will be much 
more efficient and those big heater batteries can stay home.

Merely plopping some FET transistors into a tube socket using source, 
gate, and drain as direct substitute for cathode, grid, and plate are 
not likely to work as well as they could. Subbing emitter, base, and 
collector will be even worse. Do you have references to the reports on 
the lab work showing that the 'tubesters' didn't work as well as the 
tubes? I would like to see where the deficiencies are so they can be 
resolved.

73,

Bill  KU8H

On 01/02/2017 01:42 PM, George Babits wrote:
> I've been watching this thread since it began. Wondering the overall 
> WHY of solid stating a piece of history. Tubes just aren't that hard 
> to find,  so it just doesn't make any sense at all to me.  The 
> "tubester" filled Collins gear, from what I have heard, never worked 
> as well as the same set with the correct tubes in it.
>
> George W7HDL
>
>
>
>
> ----- Original Message ----- From: "Spencer Petri" <petewa5jci at gmail.com>
> To: "Phillip Carpenter" <carpenterpa at tds.net>
> Cc: <arc5 at mailman.qth.net>
> Sent: Monday, January 02, 2017 11:32 AM
> Subject: Re: [ARC5] Transistorized ARC-5 Receiver
>
>
>> Years ago I converted an LM freq meter to solid state using MPF102s,
>> except in the audio. It was a fairly easy conversion, the calibration
>> stayed intact. The paperwork is long gone and that's all I remember
>> about it except I ran it with a 9 V battery. de Pete WA5JCI
>>
>> On 1/2/17, Phillip Carpenter <carpenterpa at tds.net> wrote:
>>> Reading and studying the Solid State Q5er article in detail shows 
>>> that the
>>> author, Bob Grabowski, W5TKP, built two versions. The first was 
>>> experimental
>>> and used first generation transistors such as 2N1639 for the mixer 
>>> and 2N384
>>> for the oscillator. Also the originals coils were altered. It was a 
>>> fair
>>> amount of work and destroyed the Command receivers original 
>>> componentry.
>>>
>>> However, a second version did not alter any of the original coils or
>>> components. Also it used FETs, namely  seven TIS34s for all the stages
>>> except the detector which used two 2N1306s.
>>>
>>> Results were claimed to be excellent. This means we could make plug 
>>> in FET
>>> substitution units using octal adapters (these are available on eBay 
>>> from
>>> China sources for 2pcs for $10.49 shipped).
>>>
>>> I'm going to start with a plug in substitute for the 12K8 and see if
>>> performance is notably improved.
>>>
>>> Phillip W4RTX
>>>
>>> Sent from my iPhone
>>>
>>>> On Jan 2, 2017, at 12:33 PM, Glen Zook <gzook at yahoo.com> wrote:
>>>>
>>>> Plastic 2N4416 transistors, which are, basically, the same as the 
>>>> MPF-102,
>>>> are still available from Mouser.
>>>>
>>>>
>>>>
>>>> Leaded J-310 are also available from Mouser for $3.47 in single 
>>>> quantities
>>>> and for $2.79 each in quantities of 10.  The surface mount J-310 are
>>>> available for as little as $0.31 in single quantities and $0.201 (yes,
>>>> $0.201) each in quantities of 10 (make for total of $2.01 for 10) 
>>>> again
>>>> from Mouser.
>>>>
>>>>
>>>>
>>>> Glen, K9STH
>>>>
>>>> Website: http://k9sth.net
>>>>
>>>>
>>>> From: MICHAEL ST ANGELO <mstangelo at comcast.net>
>>>> To: Phillip Carpenter <carpenterpa at tds.net>; Brian
>>>> <brianclarke01 at optusnet.com.au>; Jim Haynes <jhhaynes at earthlink.net>
>>>> Cc: arc5 at mailman.qth.net
>>>> Sent: Monday, January 2, 2017 10:17 AM
>>>> Subject: Re: [ARC5] Transistorized ARC-5 Receiver
>>>>
>>>>  Brian,
>>>>
>>>> That's the path I took; replaced all circuitry except the frequency
>>>> determining components such as the capacitors, inductors and 
>>>> transformers.
>>>> If someone is concerned about upgrading a set with tubes there are 
>>>> lots of
>>>> carcasses around minus the tubes to resurrect.
>>>>
>>>> MPF-102's have been obsolete for years but J310 are still being 
>>>> produced
>>>> and is a better alternative. Unfortunately the production of leaded
>>>> thru-hole devices has been discontinued but SMT devices are available.
>>>>
>>>> I purchased leaded J310s from Arrow Electronics last year. I 
>>>> checked today
>>>> and they are on backorder.
>>>>
>>>> I also stocked up an leaded bipolar transistors such as the 2N3904 and
>>>> 2N3906 at that time.
>>>>
>>>> Dan's Small Parts still has leaded devices.
>>>>
>>>> With regards to plug-in replacements I would be more interested 
>>>> with solid
>>>> state replacements for some of the transmitting tubes which are 
>>>> hard to
>>>> find such as the 211E in the BC-375.
>>>>
>>>>
>>>
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