I was unaware of this product until Jim Miller of Comtek Systems brought
it to my attention recently. It turns out that Radio Shack is closing
them out so if you are interested you may want to call your local store
and see if they still have one in stock. The catalog number is 21-527
and the price is around $50.00 I think.
This is a digital wattmeter with remote pickup head. The connecting
cable is three-conductor, about number 24 wire.
The reasons I'm bringing it to the list's attention are twofold. First,
I think Radio Shack did a bad job of advertising this unit -- I'd never
heard of it until I went into the local store and asked about it.
Second, if you are using a phased vertical array with Comtek's hybrid
coupler to accomplish the proper phase relationships, you know that you
need to monitor the power being dumped into the dummy load. So, you have
a choice of running lots of coax from the coupler unit back to the
shack, putting the dummy load there, and monitoring the power with a
conventional wattmeter. Or, you can use something like this Radio Shack
unit.
In my case, the run from the shack is 500 plus feet, and the choice of
500 feet of RG-213 or 500 feet of cheap telephone wire was an easy one.
The wattmeter has three ranges -- 20 watts, 200 watts, and 2000 watts --
as well as an autosensing position. With the touch of a button, it will
also read SWR directly. The control head display consists of backlit
LCD's about 1/2" high and the head itself is about 4" wide by 1 1/2"
high. It has a bracket on it that suggests that it was intended to be
used in mobile applications. There is also a front-panel button to
switch between peak and average reading. The remote head looks
well-sealed and relatively weather-proof, but the manual suggests
sealing with one of the compounds designed for that job if it's going to
live outdoors fulltime.
So far, the unit works as advertised and seems to fill a missing niche.
As always, YMMV, but to me -- especially at the closeout price -- this
seems like an excellent value.
Rolfe, W1VC
--
Rolfe Tessem | Lucky Duck Productions, Inc.
rolfe@ldp.com | 96 Morton Street
(212) 463-0029 | New York, NY 10014
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search
|