[ARC5] Transistorized ARC-5 Receiver

[Phillip Carpenter]

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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