An attempt to make a de cent 600 W/50 Ω dummy load («fig) by using 4 × 50 Ω/150 Watt resistors for HF failed. 0 - 500 MHz (500 MHz SWR < 1.3), continue 800 W on a suited heathsink (1500 W PEP short period). It is submerged in oil to allow somewhat extended operation during tuning or … KA9VQF Ham Member QRZ Page. 50 watts? I made my dummy loads simply by using 1 ohm 17W resistors, wired in series parallel across tag strips - with plenty of air spacing. It uses a number of non-inductive resistors in parallel to achieve 50 Ohms over a wide frequency range. An attempt to make a decent 600 W/50 Ω dummy load («fig) by using 4 × 50 Ω/150 Watt resistors for HF failed. I used to own a very good BNOS load a long time ago but I really have no idea what happened to it. Not just any resistor will do. Since my amp got all of the mentioned load capability, I was wondering if this could make any difference? (left to right in picture): 50 Ω/250 Watt, 50 Ω/150 Watt, and 50 Ω/25 Watt. It is my experience that a stripline resistor cannot handle excessive voltages in contrast to ordinary resistors. Normally these are a ceramic disc attached to a silvered copper-mounting strip. Get an 8ohm resistor that matches your amp's output wattage (i.e., 100 watts? At some time it probably was either sold or stashed in the loft, I really can’t remember. Be prepared and able to communicate in case of emergency with the largest selection at eBay.com. Shaping it into a 'U' figure if the tab is still long enough. Also, if and when I try one, should I go go for a 4 ohm, 8 ohm or a 16 ohm version? Ref. made from aluminium nitride ceramics) exists in many shapes and power ratings e.g. These are frequently used in combiners of the amplifiers in cellphone towers. 15-04-2013 With een second example of a construction. Simple dummy load and power indicator. 120 Volt. Regularly 150 Watt and 250 Watt 50 Ω resistors are offered on hamfests and eBay. In the grand tradition of finding what other hams have done and sticking with that, I built a version of a dummy load that K7AGE built, which in turn is a design he borrowed from Elecraft, a maker of kits for transceivers and other ham gear. By Lou Destefano, VK3AQZ 16/12/2010 At a recent swap meet, I was fortunate enough to purchase a UHF 50 watt, 50 ohm, dummy load, ex commercial gear, all for $10. within 1½ - 3% of 50 ohms; SWR is less than 1.03; Couldn't ask for anything more!I have run the dummy load for several minutes with my transceiver at 100 W (its max power), and there was absolutely no noticeable rise in temperature of the can. Fast & … DIY Speaker / Amplifier Dummy Load. A basic dummy load is made up from a NON-INDUCTIVE resistor with a final value of 50-Ohms, so it matches up to 50-Ohm transmitters. THE LOAD RESISTOR The performance of the dummy load has mostly to do with the resistor characteristics. Amateur radio operators (hams) or anyone who builds or experiments with radio transmitters should have and use a good dummy load. Dummy load with a 50 Ω stripline (hybrid) resistor. But, as with all things RF, details matter. This is a simple DIY Speaker dummy load that was put together very quickly. Doing so will distort the heatsink resulting in a bad thermal connection between the heatsink and the component. 2.When test and adjust the transmitter, you may receive other radios signal on your test frequency, which can cause interference. I don’t have a 50 ohm dummy load Power measurements require a dummy load. Even in the HF region the mounting of the resistors on a heatsink and using insulation washers gave too high a capacitance. A 50 ohm dummy load Make your own dummy load with two 100-ohm 5W resistors Building a dummy load Building a Dummy Load and Measuring Power Accurately by Ken, K4EAA A low cost dummy load This article describes a low-cost, low-to-moderate power dummy load, which presents a 50-Ohm resistive load from HF through 440MHz. Here some photographs of a commercial 150 watt 1 GHz dummy load: the Cellwave 150 Watt CL150. Very accurate impedance measurements thereby reducing the inductance and capacitance source the parts to build a dummy can! ( hybrid ) resistor the ready made N-connector with attached coaxial connection made construction real simple accurate impedance measurements attempted... This could make any difference on eBay listed at five for $ 1.99 levels! Two tabs and having the actual resistor isolated from the mounting of the resistor in. Can see how a 150-Watt resistor should not be exposed to a peak voltage that is than... 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