Rover Location Database |
|||||||||||||||||||||||||
Ham Radio
|
Generator Pair with 110-to-220 TransformerI have an Icom PW-1 and a Beko solid-state linear amplifier. They both require 220 vac to develop full power. How can they be used for portable ops? Where does the power come from? Overview
Estimated Power BudgetHere's a simple estimate of the expected maximum current requirements:
Therefore a single 2 KW generator will probably not have a comfortable safety margin. The load should be easily handled by a 4 kilowatt generator pair. What about connector ratings? Note that standard 110 v 3-pin line connectors are stamped with a 10-amp rating. Note the Honda generator's recepticals have "20A 125V rating", but the generator's inverter has 13.3A average current rating. This is significantly less than the estimated 16A requirement. Honda EU2000i Generator PairSince I usually travel and setup alone, my top requirements are portability, size and weight. In addition, I really want low acoustic noise. I examined several alternatives. However, all the various choices were too too heavy, too expensive, and took up too much valuable truck space. Source: New cost at local Honda small-engine dealer was $2199 total. I found a pair on Craigslist for $1400 including connecting cables. Line Noise FilterInitial tests had no problems with rf noise without using a line filter. I can always add this later, if needed. Later: There were no problems with rf noise. 110-to-220 Step-up TransformerMy linear amplifiers require 220 vac, but these Honda generators only produce 110, even when connected together. A step-up transformer is needed. The transformer should be located alongside the generators, so the extension cord will carry lower current at higher voltage. This will reduce the I2R losses. That is, resistive heating (I2R losses) mean that 2x voltage yields 0.5x current, which means 1/4 of the resistive energy loss. My transformer is a Simran SMVS-3000 with meter, fuse, voltage regulator and stabilizer, rated for 3 Kva. This is a cheap Chinese device but I'm hopeful. No Load Power Measurements made with "Kill A Watt P3" on wall outlet:
Loaded with Beko amp plugged in, turned on, standby:
Loaded with Beko amp plugged in, turned on, not standby:
Source: Craigslist for $80 or Amazon for $95. 220v Extension CordI bought a 50-foot yellow extension cord of 12-gauge 3-wire design. I cut off the ends and connected NEMA L4-20P locking connectors. The current rating is overkill but I have standardized on L4-20P connectors throughout all my generator and 220v devices. Since I have two linear amplifiers, there are two receptacles on the equipment end. Source: Home Depot and many other hardware stores sell extension cords. This one was $65. Each NEMA L4-20P locking connector was about $19. Beko 750 watt SSPABeko 750 watt SSPA s/n 051010
ConclusionOutstanding. My first usage was in the 2015 ARRL June VHF Contest. The whole system ran superbly, it was trouble-free, and all the various parts worked smoothly and without complaint, and I received good signal reports. Nothing seemed to be loaded heavily or working hard. SSB: The pair of generators didn't seem to notice the 750-watt SSB load. I could run this Beko with a single generator on voice. CW: I could notice the pair of generators would throttle up slightly in response to CW keying. If I shut off one generator, it was working noticeably hard to respond to CW, but it would keep up and the amplifier was satisfied with the power source. Personally, I felt more comfortable using both generators together when operating CW.
|
||||||||||||||||||||||||
|
|||||||||||||||||||||||||
Last Update 2015-06-28
©1998-2024 Barry Hansen |