[TowerTalk] 60/40 solder

[Michael Tope]

Peter Voelpel wrote:

>It will not take much power to get way more then 1A through a piece of
>copper wire in a RF tuned system.
>>From my experience, soft soldered connections won´t last long when outside
>and when the solder joint is not weather proof protected.
>
>73
>Peter
>
>
>
>Jim Miller KG0KP wrote:
>
>  
>
>>Now we mix Tin(60)/Lead(40) and get 10.6 microhms per centimeter.  Now 
>>the distance we are talking about is NOT 1 cm.  Not even one mm but
>>lets use that anyway ( more like 0 to 1/10 mm).   So, we have 1.06 
>>microhms.  Now it will take approximately 1,000,000 volts to get an 
>>amp at that point. 
>>    
>>

More like 1000 amps to get one watt dissipated in a 1 microhms 
connection (I^2*R)[voltage drop would be 1 millivolt across the 1 
microhm joint]. With 1000 watts of drive you would need a system 
impedance of 1 milliohm to get 1000 amps flowing. That's an impedance 
ratio of 50,000 relative to the amplifiers output impedance.

A cold solder joint seems more likely. I may be wrong, but it seems like 
you'd have to work really hard on a low-impedance transformer design in 
order to get 1000 amps flowing from a 1KW 50 ohm source.

73 Mike, W4EF...................