[AMRadio] Rolling your rig home in the West

[Donald Chester]

>From: "John T. M. Lyles" <jtml at vla.com>
>Spent some time building a 1 kW dummy load, to test it to full output. That 
>was a moderate success as the two 12 inch Globar-like resistors I settled 
>on had horrible tempcos, and VSWR would drift up as they got hot (107 deg C 
>on the surface, had a high velocity fan blown on them). I have been 
>wondering where I could find one of those toaster element (Ohmweve 
>resistors) built-in dummy loads like Gates used to build into their BC 
>rigs. Anyone got an extra one for cheap?


You are probably exceeding the rating of the Globars.  A 12" one is rated 
only at about 150 watts, so if you are running a kw into 2 of them that is 
about a 150% overload.  I built one out of a dozen 600-ohm globars wired in 
parallel.  That should be rated at about 1800 watts continuous.  I was given 
the grobars n.i.b. (dated 1945) from the estate of an old gentleman after 
all his "good" stuff (i.e. SSB xcvr and linear) had been sold.  It measures 
50 ohms exactly using a DVM, and the SWR doesn't change even after running a 
kw into it for hours.

Don K4KYV

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