This load looks very similar to units that I came across in the 80's when
working for the Swedish military.
If it corresponds to this general type, it is a peak reading termination
wattmeter intended for
UHF pulse transmissions, and it is not intended to handle more than about 50 W
or so average power, corresponding to a max duty cycle of 1 %.
A 5 kW air cooled average load would be a very different creature, with lots of
cooling fins...
There are no simple ways to convert this unit to a "thru-line" wattmeter, as it
does not contain a directional coupler.
73/
Karl-Arne
SM0AOM
----- Original Message -----
From: "Steve Katz" <stevek@jmr.com>
To: <craxd1@verizon.net>; <amps@contesting.com>
Sent: Wednesday, August 17, 2005 8:02 PM
Subject: Re: [Amps] [BULK] - Sierra Electronics 5kW load/meter
> I don't know this specific load, but the fact that the meter range switch
> doesn't have any provision for "reflected" may well indicate that this unit
> is not measuring power using a directional coupler, but rather as a
> calorimeter, measuring thermal rise in the load. If that's the case, there
> would be no way at all to make it an "in line" instrument, since the only
> way it would indicate is by dissipating power in the load and measuring
> heat.
>
> I'd recommend dismantling the thing to see where the meter is getting its
> current from...
>
> WB2WIK/6
>
> -----Original Message-----
> From: Will Matney [mailto:craxd1@verizon.net]
> Sent: Wednesday, August 17, 2005 10:36 AM
> To: amps@contesting.com
> Subject: [BULK] - [Amps] Sierra Electronics 5kW load/meter
>
>
> All,
>
> I just won a rackmount, 5kW termination load, with peak reading wattmeter
> off ebay. The load was made by Sierra Electronics, division of Philco. The
> model is a 400A-Z. I'm now looking for a manual on this and checked at Bama
> with no luck. Do any have any info on this load/meter, or where one might
> find it? A link to the item is below to see which one it is by the pics. I
> also need to buy a new converter plug from a N connector to a UHF type
> SO-239 female. The one I have here is in pretty poor shape and need a good
> cheap place to buy one. Last, I wonder how hard it would be to convert this
> to a thru line type so it can be switched between load and antenna? Thanks
> all for any help.
>
> http://cgi.ebay.com/Philco-400A-Z-Peak-Power-Wattmeter-Rack-Mount-5000-Watt_
> W0QQitemZ7537709171QQcategoryZ1504QQcmdZViewItem
>
> Best,
>
> Will
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Anti-Virus.
> Version: 7.0.338 / Virus Database: 267.10.12/75 - Release Date: 2005-08-17
>
>
--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.338 / Virus Database: 267.10.12/75 - Release Date: 2005-08-17
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|