Topband: Silver solder

[Joshua M. Arritt]

On BC MW AM installations, I use 15% Ag StaySilv bars for brazing 
radials together, or to a common feed/EQ strap ring at the base of the 
antenna, or strap running along a center line between two members of an 
array where the radials will intersect.

I'll use alternately a Oxy/MAPP torch set, or small Oxy/Acetylene set, 
conservatively valved, to get enough heat to braze.  Torch choice is 
based on which set is on the truck and which set has gas....

The same method/material is used for strap-strap joints, and along 
angled strap folds, on both AM and FM BC site grounding jobs.

The keys/goals of this method are absence of Pb, and insurance of good 
enough heat to totally flow the solder/Cu grounding system member.

This method was taught to me by  broadcast "wintergreen".

My amateur radials, on the other hand, use far more dubious "cheap" 
methods -- methods which I am embarrassed to publicly divulge -- on 
account of a total lack of a working budget for things like welding gas 
and silver brazing solder..  ;)

   73,
   - Josh / KF4YLM




On 1/1/2015 8:52 PM, Mike Waters wrote:
> The silver solder I have here does have a high silver content, yes. :-)
> It also contains cadmium, which shouldn't be used indoors because the fumes
> are toxic.
> It's 1/16" diameter round wire. When it's gone, I'll probably replace it
> with a cad-free alloy.
>
> I mostly heat the work (that is, the junction of ground radials, wire, and
> ground rod), and let that melt the solder. Applying a flame to the solder
> itself is an exercise in frustration. You're not doing that, are you?
>
> 73, Mike
> www.w0btu.com
>
> On Thu, Jan 1, 2015 at 4:37 PM, Paul Christensen <w9ac at arrl.net> wrote:
>
>>    > “If you had trouble with an oxyacetylene torch, then I'll bet you
>> used "silver-bearing" (tin-copper-silver) solder, which melts at well under
>> 700 degrees.
>>
>>   These are mid-level silver sticks with 15% silver + copper/phosphor and
>> have a working temperature of 1200-1400 degs. F – but not the 2-5% silver
>> bearing variety with a lower melting point.  You are probably using a much
>> higher silver content if working with OxyAcet.
>>
>>   Using OxyAcet on the 15% bars can quickly result in boiling and
>> vaporizing of the solder with damage done to the copper, especially to a
>> copper strap.  With 15% bars, Acetylene/air works fine even with a high
>> amount of heat-sinking.  I have not yet tried MAPP gas.
>>
>>   Paul, W9AC
>>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband