Cost

[Dave Cheitel]

Hello all,

I was curious. To anyone that has completed one of these amps, what was your rough cost of materials?

[jcve...@gmail.com]

I decided to wait a few days to see if anyone else would chime in.

The cost depends on how you shop. The EA2-12 relays are a big cost driver in building the LPF and T/R boards. They are almost $2.50 ea. at Digikey but can be had for less than a buck on AliExpress (the ones I've gotten from AE have been fine).

With careful shopping, you should be able to build the amp board with a heatsink for $50. The T/R parts are less than $20 and the LPF for $50. So about $150 for the three boards and the parts. 

This is where the cost becomes more variable. A case can range from free to $50, power supply, connectors, hardware probably another $50 if you have to buy everything. The control system is also a big variable, an Arduino Nano with a 1.96" OLED is pretty cheap and can get the job done. You could add a IDD monitor board, multi antenna switching, a scheme to support two radios simultaneously; the possibilities are endless. 

The short answer is $200-$300 depending on how well stocked your junk box is. To look at it in another form of currency, let me define 1 HWA (hundred watt amp) to be equal to the cost of the Elecraft KXPA-100. This amp should run you 0.15 to 0.25 HWA's the Xiegu 100W amp is about twice as much at 0.5 HWAs.

So in this case, you really can save some money by homebrewing.

73,

Jim WA2EUJ

[Nick Kennedy]

It depends on what all you include under the label 'amp', but I can give a few numbers, I have a good junkbox but I did buy most parts that mount on the board from Mouser.

For the 100 W amplifier board, I spent $38.71 excluding shipping and price of the board itself.

I also built the SWR/power meter + T/R switch board.  For it excluding shipping and the board itself I spent $12.46.

I'm a hamfest bargain shopper and have a cardboard box full of heat sinks and pulled out a nice one for this project which I may have given $1 for.

I needed 50 VDC and found a Meanwell 48 volt 4.2 ampere P/S for under $30 IIRC.

I'm not totally sure how I'm going to do the LPFs. I have a few ugly, unmatched ones lying around and I may put them in a box with a wafer type bandswitch (hamfest prize) or I may eventually build a properly designed relay switched LPF board.

So far I'm feeling OK about my costs.

73

Nick, WA5BDU

[Dave Cheitel]

thank you both for your input and data. as there are so many gabage 100 or less amps out there i.e. the chinese ones on ebay that are known for blowing power transistors in a slight breeze, I was very intrigued by this design. regarding some of the parts, i found a couple of the simple small parts to be supply chain issues right now. im a newer homebrewer but vetran to electronics, i get stumped with things that are not clearly defined, like for instance, where to get the heat sink with stand-offs that the amp board mount to (thats for starters lol) if anyone cares to be a mentor for some following in footsteps i do appreciate the guidance. Thanks in advance for any info or questions answered.

73

Dave AB6KX