I have on order -- and hope to receive in about 3 weeks -- Elecraft's K144XV 2 meter internal transverter module for my K3. I'm beginning to look at available alternatives for an external 2 meter amplifier, and would appreciate any experience anyone on the list has with any of the following:
1. Communications Concepts 875A (10 watts in, nominal 75 watts out, $120 for a complete kit, $160 assembled) 2. Mirage B1018G (10 watts in, nominal 160 watts out, $350 new from some dealers) 3. Maha MH-A103 (5 watts in, nominal 50 watts out, several used units currently available on eBay under $100) 4. KLM PA 2-70BL (4 watts in, nominal 70 watts out, one used currently available on eBay, BIN of $100) Any other amps I should be considering? "Must have" criteria: will operate on 13.8VDC power, requires no more than 10 watts input to achieve maximum rated output, interface easily with K144XV. Nice to have criteria: compact, quiet, less than $400 street price. Max power output isn't all that critical to me; this will be used for VHF contesting, not EME, so I don't need or want a 1KW or 1.5KW tube-based amplifier. Based on my experience in VHF/UHF contesting, I think that either 75 or 150 watts out would be a big improvement over 10 watts, but that there wouldn't be all that much difference in results between 75 and 150 watts. Yes, I'd love to have 500 or so watts, but the price tag is too high for my budget at the moment, given what I need to add to my K3. Based on specs and price (that is, most watts output for the buck) I'm leaning toward the CC 875A kit, but I can't find any reviews that discuss its performance and reliability. It's uses a Motorola MRF247 MOSFET, and is based on a circuit design in Motorola's Application Note AN791. CC has added some features to the basic design published by Motorola, but the basic amp is what's described in AN791. I like the fact that it's compact (6 x 3 x 4.25"), and that it draws only 9 amps at maximum output. The cost per watt of output is $1.60 for the kit. The lack of a pre-amp doesn't seem too significant to me, given that the K144XV specs show -144 dB sensitivity (14 dB improvement over the main rig's -130 dB specs). Is anyone familiar with this product? The Mirage B1018G has a lot more output when driven by 10 watts in, and it includes a receive pre-amp with jumper-selectable gain ranging from 2.5 to 14 dB -- duplicative of the receive amplification in the K144XV -- but it's also more expensive, and a lot bigger and heavier (12 x 3 x 5.5, 5 lbs.) The cost per watt of output is $2.19 given the best dealer price I can find (which isnb't Mirage itself). Given that Mirage is owned by MFJ, I'm also a bit leery of construction quality and reliability. At full output this unit requires 30 amps, which is a minus factor for me. The amps/watt is about 1.5 times the power supply requirement of the 875A. The used units mentioned have their own attractions, but both are long out of production, and thus support would be zilch, so they are lower on my list, subject to input from this group. Comments and "user reports" welcome. Lew Phelps K6LMP Pasadena, CA DM04wd Elecraft K3-10 (160-6 meters, soon to be 160-2 meters, all modes) Yaesu FT-7800 (2m and 70 cm, 50 watts FM only) ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
