Aw: LF: Dummy load

["Hans-Albrecht Haffa" <dk8nd@web.de>]

Dear OM Elmer,

depending on the power You intend to use, I recomend homebrew Dummy Loads, indeed attenuators only up to a power of 100 Watt. Wovings of bifilar wound fibre glass filaments and Nickel Wire (Manganin or Konstantan) are recomended in HF-Books before WW2 for LF and MF. Add a power meter at the low power output of the attenuator.  At Ham  Radio in Friedrichshafen I acqured two DL 60 Ohm /100 W dry and a big boat anchor of 60 Ohm/1,3 kW, wet , both from Rohde und Schwarz. The power dissipation is for measurement purpose (cw 24/24h) for ham radio measurements the power is larger. As Power meter I use one of Sat-Technik Ulf Schneider, in see Internet    www.sat-schneider.de    . Of course I have put some attenuators of minor power at the output of the Dummy Loads. On LF/HF-frequencies I prefer stable test set ups, with 50 Ohm or 60 Ohm resistance in matching and measuring. Please dont waste time in ham construction, I remember plenty of them for Dummy Loads in HF. More upon request.

 

55, Hans-Albrecht DK 8 ND

 

Gesendet: Sonntag, 25. November 2018 um 03:27 Uhr
Von: "Musser, Elmer (HBO)" <Elmer.Musser@hbo.com>
An: "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>
Betreff: LF: Dummy load

Saw dummy load conversation and I too am wrestling with .. what about Nichrome C wire, 26 gauge 19 feet to come close to 50 ohms? Resistance change due to temperature should be low. Thinking of mounting outside to mange heat.

Elmer
N3AGE


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