[R-390] Fwd: Sherwood

[Grant Youngman]

Oops .. forgot that pesky "reply all"

Begin forwarded message:

> From: Grant Youngman <nq5t at tx.rr.com>
> Subject: Re: [R-390] Sherwood
> Date: October 20, 2013 10:05:45 AM CDT
> To: Bob Camp <ham at kb8tq.com>
> 
> When I first purchased my SE-3, it came without the "bass boost" circuit.  I queried Rob about it, and the problem was that the supplier of the inductor used for the circuit was no longer supplying.  Eventually he was able to resource the part, and sent me a kit to add it my SE-3.
> 
> Since then, I've added the AR circuit so it locks more quickly in roundtables, and had Rob modify it so it is switchable between 455Khz and 500Khz and I can use it on my 51J4 in addition to the 455KHZ IF radios around here.
> 
> The best thing about it is that it WORKS (really really well), doesn't require cobbling together an SDR interface between the radio and a PC, and most of all is not sensitive to software problems or the vagaries of Windows Update.  There are advantages to the relative simplicity of well designed analog circuits.  You just plug it into the iF and listen.  A side advantage is that it does an excellent job on SSB on old radios, too.  
> 
> Grant NQ5T
> 
> 
> On Oct 20, 2013, at 9:25 AM, Bob Camp <ham at kb8tq.com> wrote:
> 
>> Hi
>> 
>> Which is why you probably should re-design it with up to date parts if you wanted to keep selling them. SMT has pretty much taken over in the world of semiconductors. There are some parts (or even categories of parts) that simply are not available in a "hand solder" sort of package. Yes for a home build you can find this and that. For a commercial product that's expected to last, off to the pick and place machine ….
>> 
>> None of this is a knock on the fine design job he did on the SE-3, it's just the way the semiconductor business has gone over the last two decades. I doubt that we have done a single "non SMT" design at work in the last 10 years. We've probably done several thousand SMT designs. Just to be clear - to me SMT is anything that is fine enough pitch that hand solder is not economically practical. By that definition a SOT-23 is not a hand solder part (yes I've been hand soldering them since the 1970's) in a deliverable product. 
>> 
>> Bob
>> 
>> On Oct 20, 2013, at 9:33 AM, frank hughes <fsh396ss at gmail.com> wrote:
>> 
>>> Hi,
>>> One of the interesting things Rob mentioned to me when I bought an SE-3
>>> years ago was component availability.
>>> 
>>> T