[Elecraft] recommendation of a low cost iambic paddle / BeengaliSimplex shipping with gold contacts

[Joe Subich, W4TV]

> If the 'regular' contacts are the same as what was previously 
> supplied with the various Begali magnetic paddles, they have 
> problems with many keyers, including the K2's internal keyer, 
> the Logikey, and others. So the gold contacts are a very good 
> investment.

The "issue" with the regular Begali contacts (as well as those used 
by Schurr and others) is that they appear to be of an alloy that 
forms a semi-conducting surface.  That results in contacts with a 
minimum voltage drop - independent of current - of around .5 volt. 
That 1/2 volt offset is too high to allow low power CMOS inputs 
(e.g., Logikey and others) to reliably register a logic "Low" and 
is enough of an offset to upset the decision point on PIC based 
keyers with a multiplexed (analog) paddle input (e.g., WinKey and 
others).   

The solution is to add a schmidt trigger inverter and FET driver 
(or dual comparator) in line with each paddle contact.  

73, 

   ... Joe, W4TV 
 


> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Vic K2VCO
> Sent: Friday, October 26, 2007 12:18 PM
> To: Chris Wagner
> Cc: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] recommendation of a low cost iambic 
> paddle / BeengaliSimplex shipping with gold contacts
> 
> 
> Chris Wagner wrote:
> > I ordered the regular Simplex and paid a few bucks
> > more due to making an EU payment. Anyhow, they will
> > send me the model with the gold contacts as this is
> > the one they have in stock, while the regular contacts
> > will be manufactured in a few weeks. So if you plan to
> > get one of these, ask if you could get the upgrade.
> 
> If the 'regular' contacts are the same as what was previously 
> supplied 
> with the various Begali magnetic paddles, they have problems 
> with many 
> keyers, including the K2's internal keyer, the Logikey, and 
> others. So 
> the gold contacts are a very good investment.
> 
> If you're interested in details see my review of the Begali Magnetic 
> Professional, about the 5th one down at 
> <http://www.eham.net/reviews/detail/3468>. Other than the non-gold 
> contacts, I love this paddle.
> -- 
> 73,
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco