{"id":103803,"date":"2021-04-29T21:20:15","date_gmt":"2021-04-29T21:20:15","guid":{"rendered":"https:\/\/www.snapwhole.com\/index.php\/ham-radio-digital-mode-frequencies\/"},"modified":"2023-01-17T01:05:10","modified_gmt":"2023-01-17T01:05:10","slug":"build-an-8-watt-dummy-load-for-the-ubitx-v5-v6","status":"publish","type":"page","link":"https:\/\/www.snapwhole.com\/index.php\/build-an-8-watt-dummy-load-for-the-ubitx-v5-v6\/","title":{"rendered":"Build an 8 Watt Dummy Load for the uBitx v5 v6"},"content":{"rendered":"\n

Build an 8 Watt Dummy Load for the uBitx v5 v6<\/strong><\/mark><\/p>\n\n\n\n

Return To Ham Radio Projects<\/a><\/d3><\/center>

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8 Watt Dummy Load for uBitx v5 v6<\/figcaption><\/figure><\/div><\/div>\n\n\n\n
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The assembly directions for the uBitx v5 warn the unit could go into transmit if powered up without the Key connector wired, so I needed to build an 8 Watt Dummy Load to handle this, just in case<\/p>\n\n\n\n

I keep various resistors on hand suitable for making dummy loads, 2 watt, 3 watt, 51 ohms, 100 ohms, 200 ohms, 2K ohms<\/p>\n\n\n\n

Resistors have a very useful property, when resistors of the same size and wattage are wired in parallel, the Watt rating the aggregate watt value of all the resistors, and the ohm rating is divided by the total number of resistors<\/p>\n\n\n\n

Example:\n2 100 ohm 2 watt resistors wired in parallel will create a dummy load rated at 50 ohms and 4 Watts\n2 100 ohm 3 watt resistors wired in parallel will create a dummy load rated at 50 ohms and 6 Watts\n4 200 ohm 2 watt resistors wired in parallel will create a dummy load rated at 50 ohms and 8 Watts<\/pre>\n\n\n\n
This one is good in theory, but not in practice, the heat generated at 80 Watt would destroy the resistors<\/pre>\n\n\n\n
40 2000 ohm 2 watt resistors wired in parallel will create a dummy load rated at 50 ohm and 80 watts<\/pre>\n\n\n\n
Endless combinations\u2026\u2026.<\/p>\n\n\n\n
1 BNC \u2013 right angle\n4 200 ohm 2 Watt Resistors\n1 Head Shrink Tubing<\/pre>\n\n\n\n
Not a lot of parts\u2026..<\/p>\n\n\n\n
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8 Watt Dummy Load Parts<\/figcaption><\/figure><\/div><\/div>\n\n\n\n
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To install the resistors, solder one end of each resistor to the center pin of the BNC and the other end of the resistor to the shield<\/p>\n\n\n\n
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8 Watt Dummy Load soldering<\/figcaption><\/figure><\/div><\/div>\n\n\n\n
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While it is not required to cover the resistors with heat shrink tubing, it is a good idea, eventually someone will be an RF burn from the exposed wires<\/p>\n\n\n\n
So I installed the heat shrink tubing and used my soldering iron to shrink the tubing to cover the resistors<\/p>\n\n\n\n
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8 Watt Dummy Load for uBitx v5 v6 Shrink Wrap<\/figcaption><\/figure><\/div><\/div>\n\n\n\n
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Construction of the 8 Watt Dummy Load for the uBitx v5<\/p>\n\n\n\n
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