DX-100 Resistor Source

[Kenneth G. Gordon]

On 22 Jan 2007 at 20:06, Mike wrote:

> Does anyone know where to buy replacements for the 5.4 and .092 ohm
> resistors that are used as meter shunts?

When I need such, I make them. 

The .092 ohm shunt can be made out of a certain length of hookup wire 
of the appropriate diameter, wound on a form like a pencil or something 
similar, then tied or glued down. I usually adjust them "in place", so to 
speak, before winding them on any sort of form, with an accurately 
calibrated VOM or VTVM in series with the meter I am trying to shunt.

The appropriate size of wire can be chosen from a standard wire table, 
one of which is always in the back of every ARRL Handbook. The wire 
is listed at so many ohms per foot, or per 1000 feet. The smaller the 
diameter, the more "ohms per foot".

The 5.4 ohm resistor can be made in a similar way, although I normally 
use the closest common value of resistor from Radio Shack, but on the 
LOW side, and adjust it with a series wire as above.

Although you could undoubtedly BUY a precision, special order, shunt 
resistor, it would be FAR more expensive than making them by hand, 
and in addition, often they aren't any more accurate when you take the 
resistance of the connections into account.

In some instances, just to see how it would work, I finished adjusting my 
meter shunts with a file. Such accuracy far exceeds the read-out 
accuracy of the meter itself, and is totally unnecessary, but can be fun.

Ken W7EKB

-----------------------------------------------------------
Products bought, sold or traded here is the responsibility of the
parties involved.  This list and the City of Tempe are not responsible
for losses or misrepresentations of any kind.  Buyer beware!

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.asp?list=HEATH
To post - HEATH at LISTSERV.TEMPE.GOV
Archives - http://listserv.tempe.gov/archives/HEATH.html