[sebhc] [Fwd: ANSWER: General Comments from Mouser website.]

[Carroll Waddell]

This part number can from someone in the group, but I'm not sure who it 
was. I believe they used to work for Heathkit.
Carroll

Scott LaBombard wrote:

>Carroll ... the part number that you provided was for the gold plated
>part. Curious ... if you have the tin plated motherboard pins, why are
>you searching for the 2251?
>
>
>Scott
>
>----- Original Message ----- 
>From: "Carroll Waddell" <CarrollWaddell at sc.rr.com>
>To: <sebhc at sebhc.org>
>Sent: Monday, April 19, 2004 9:06 PM
>Subject: Re: [sebhc] [Fwd: ANSWER: General Comments from Mouser website.]
>
>
>  
>
>>Some H8's may have had gold contacts, but the 3 that I have all had tin
>>plated contacts.
>>CEW
>>
>>Scott LaBombard wrote:
>>
>>    
>>
>>>Dwight ...
>>>
>>>Without hauling out one of my H8's to confirm ...I believe that the
>>>stock motherboard uses gold pins.
>>>
>>>I assumed that Carroll provided the correct part number  ...which
>>>would seem to confirm that belief.
>>>
>>>Otherwise, I agree with your comments. That's why I mentioned
>>>using tin contacts as a last resort (if at all)...
>>>
>>>
>>>Scott
>>>
>>>----- Original Message ----- 
>>>From: "Dwight K. Elvey" <dwight.elvey at amd.com>
>>>To: <sebhc at sebhc.org>
>>>Sent: Monday, April 19, 2004 6:14 PM
>>>Subject: Re: [sebhc] [Fwd: ANSWER: General Comments from Mouser website.]
>>>
>>>
>>>
>>>
>>>      
>>>
>>>>>From: "Scott LaBombard" <labomb at rochester.rr.com>
>>>>>
>>>>>Folks,
>>>>>
>>>>>A quick glance at http://www.molex.com/product/pcb/4455t.html shows
>>>>>          
>>>>>
>that
>  
>
>>>>>there are a couple of alternatives for this part. If you want to forgo
>>>>>'select gold'
>>>>>and instead go for the plain old 'gold' contact part, then your part
>>>>>
>>>>>
>>>>>          
>>>>>
>>>number
>>>
>>>
>>>      
>>>
>>>>>would be 22-18-2253.
>>>>>
>>>>>The folks at http://www.arrow.com/aws/pg_welcome have this part in
>>>>>          
>>>>>
>stock.
>  
>
>>>>>In addition, they sell to individuals and have no minimum order
>>>>>
>>>>>
>>>>>          
>>>>>
>>>requirement.
>>>
>>>
>>>      
>>>
>>>>>They show a price of $4.27 per unit.
>>>>>
>>>>>There's also a tin contact variation as a last resort ...
>>>>>
>>>>>
>>>>>Scott
>>>>>
>>>>>
>>>>>
>>>>>          
>>>>>
>>>>Hi
>>>>As I noted, you should only use gold if the mother board also
>>>>has gold pins. Never mix metals on pin contacts. Contacts go
>>>>bad fast enough as it is without adding electrolysis.
>>>>For those that worry about contact and want to protect their
>>>>older machine, placing some Dow-Corning #4 silicon grease on
>>>>the pins will improve contact and protect them from normal
>>>>electrolysis. There are issues in a salt air environment
>>>>but I've not had any problems and I live within 2 miles of
>>>>the coast. The grease has no other electrical problems and
>>>>is itself, non-conductive. I use it on, switch connacts, TV
>>>>tuners, EPROM pins, card edge connectors, lamp sockets, power
>>>>connectors, screws that hold regulators or power transistors
>>>>and just about anywhere that one has metal to metal that
>>>>has to carry current. I have a HiFi amplifier that has a
>>>>toroidal transformer. This used to cause the power switch
>>>>to arc and stick together ( I suspect the core was saturating
>>>>on the first cycle ). I put the grease in the switch and
>>>>it has been working fine for over 10 years now. When I
>>>>worked at Intel, we did some studies on card edge connectors.
>>>>The normal gold on gold contact had about 10 to 15 milli-ohms
>>>>of resistance. With the grease, this dropped to under 2 milli-ohms.
>>>>This was true even after the environmental chamber at 90%
>>>>humidity where the normal gold on gold would degrade to around
>>>>30 to 50 milli-ohms. They chose not to use it there because
>>>>once it got on a surface, one could not get lettering stamps to
>>>>work. This isn't an issue for us because we rarely add such
>>>>to our machines.
>>>>Dwight
>>>>
>>>>
>>>>--
>>>>Delivered by the SEBHC Mailing List
>>>>
>>>>
>>>>        
>>>>
>>>--
>>>Delivered by the SEBHC Mailing List
>>>
>>>
>>>
>>>      
>>>
>
>--
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>
>  
>