[Elecraft] Freq. counter probe capacitor

[Tom Hammond NØSS]

At 07:40 AM 10/8/02, Don Brown wrote:
>When building the probe hold the tip in a small vice or a alligator clip 
>and fill the cup with solder (you can also wrap several turns of rubber 
>band around the handles of your needle nose pliers to hold them closed 
>gripping the probe tip). Clip and quickly tin the cap leads. Then heating 
>only the probe tip insert the cap into the cup. Pre tin the center 
>conductor of the cable and quickly tack solder the cap and center 
>conductor. This should prevent overheating the cap.

Good reminder, Dan.

Another device which I find to be a "MUST HAVE" for any builder (anyone 
soldering to solid state devices), is at least one pair of hemostats 
(medical term for the long, slender, plier-like locking clamps used in 
hospitals).

Hemostats are lightweight, have a nice long, slender nose, and can be 
locked so they don't release when you remove your fingers from them. They 
can easily hold on to the lead of a temperature-sensitive component as you 
are soldering it, to help 'sink' away the hear before it can get to the 
device and possibly damage it.

Fortunately, most devices nowadays are pretty sturdy when it comes to their 
ability to withstand a bit of soldering heat without self-destructing. But 
my hemostats ALWAYS come into play when I'm trying to solder to a short 
piece of shield braid coming from a length of RG-174 (the small diameter 
coax cable). Without a hemostat secured BETWEEN the body of the coax and 
the point on the shield being soldered to, the heat from soldering will run 
right down the shield, melt the center insulation of the coax and can cause 
a short between the two conductors. RG-174 and similar type cables (incl. 
audio cables) are particularly bad for being susceptible to such damage 
from soldering if some sort of heatsink is not provided during soldering.

Additionally, I cannot count the number of times I've used one or more 
pairs of hemostats to hold a component (or wire) steady while I was either 
tinning or soldering it to something else. They're invaluable! And, they 
can often be found for a very reasonable price at hamfests. Try to find the 
type of hemostat which has a 3/4" to 1" long nose and which is easy to 
open/close/lock. Some hemostats are much too strong and will apply 
excessive compression on components and their leads.

I once bought a pair of hemostats with a really short (3.8") nose. They 
were made in Pakistan, but the price ($2.50) was right. Got them home and 
tried them out. First use... the nose BENT and stayed bent when they were 
released. Turns out these particular hemostats (actually, I think these 
should probably have been called 'pickups') were specifically used for 
catching suture thread and weren't intended for the same type of use as 
regular hemostats as they were only designed for holding threads and not 
anything larger. I certainly would NOT recommend use of this type of the 
device.

I probably now have 8 set of hemostats, of all different sizes ands 
lengths. They have all seen heavy use over the past 30 or so years.

HIGHLY RECOMMENDED for builders.

73,

Tom Hammond   N0SS