[TenTec] 238 Tuner Mod

[Bob McGraw - K4TAX]

Some years ago when working for Sony, we suddenly started having IC socket 
failures in one of our analog multitrack machines.  The problem was 
identified as failure of the IC sockets used in the analog audio.  When 
questioning the various departments as to why the Augut socket was changed 
to a different model, the purchasing manager said "well, that was the best 
IC socket we could buy for under a nickel.  We saved some $10,000 per year 
by making this change".    The Augut 800 series was selected as a 
replacement at a cost of $0.23 each in quantities of 100,000.  We had 
service engineers travel all over the world to replace some 500 pieces in 
each machine.  That's $115 in parts plus about 16 hours labor plus travel 
expense.  That totaled about $1500 per machine and some 350 machines to 
re-work.  So those nickel sockets cost us about $525,000 not to mention the 
intangible value of unhappy customers.

I'm sure those of us in of have been in manufacturing and or design have 
like stories about the finance department making engineering decisions.  In 
the case of the 238 tuner components, in likely 75% or more cases the 
selection of capacitors does not give a problem and thus would seem like a 
reasonable success factor of probability to proceed with the choice.  It is 
the 25% that causes the grief.

In my case the 238 tuner on one antenna never shows the heating or SWR 
changing problem regardless of power.  On the other antenna on 160M and 75M, 
watch out as SWR will soar with about 800 watts of carrier or more.  Below 
that, no problem is observed.  One of these days I'll change them out to 
some good quality RF rated caps.  Of course in looking at the solution, I 
would be adding about $65 in cost to tuner as well.  That passed along to 
the customer could equate to a cost increase of $100 or so.  That's a lot 
for a $400 box at retail.

73
Bob, K4TAX




----- Original Message ----- 
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
To: <tentec at contesting.com>
Sent: Wednesday, March 05, 2008 10:07 AM
Subject: Re: [TenTec] 238 Tuner Mod


> On Tue, 2008-03-04 at 19:28 -0800, Ron Castro wrote:
>> I think the cost calculation was the bigger driving force in that 
>> decision!
>>
>>          Ron  N6IE
>>       www.N6IE.com
>>
> I've heard many an engineer's tale where a quality capacitor was
> specified and necessary and purchasing bought something a great deal
> cheaper. Sometimes wasting months of engineering time waiting for the
> quality capacitor to be made, once management convinced purchasing that
> the expensive capacitor couldn't be replaced by a 29 cent part.
>
> 73, Jerry, K0CQ
>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>