Brian from Telstar Electronics has been selling off his PCB's for his Skywave 350DX on Ebay. He sold parts kits for a while and not just PCB's. For the price he is selling them at I would highly recomend people grab a few for future builds. It is not often you get an affordable PCB that has true thermal tracking AB bias, swr protection, thermal over load protection, and can be ran reversed polarized with no issue not just a diode you hope will pop before you tear up too much stuff. I have 4 PCB's and am thinking about combining two of them for a 4 transistor amp. Thinking about giving tuned input for HF+6m for each band instead of using transformer coupling for rather inefficient dirty broad banding just depends on how special I want feel....LOL I like lights and selector switches!!!
If I can find some classes not 2 hours away I want to take the test and get my ticket punched. In the mean time I am just sitting on the parts. I think he has been selling them from $10-$17 with the higher prices including free shipping I think and the lower prices having separate shipping but do not quote me. You could combine as many 2 transistor boards as you like for home or mobile use. Since they are bipolar's you have a lot of options with some of the Chinese options getting pretty good ok decent! You would have to ask Brian if the board's construction can sustain 28V continuous if it can with the right parts obviously than maybe it could be reworked for MRF150 since I think the case for the 28V MRF150 LDMOS is the same as the MRF421 and the 2SC2879 etc....Also the MRF421 which is bipolar can take up to what 28V again the rest of the parts would have to be able to live under those conditions but something to think about. I am thinking about that myself. Not every day you see a true class AB biased bipolar amp with SWR and thermal over load protection etc...that can live a long happy life at 24 volts! LOL It is not at all hard to find 24, 28, 32 and 50 volt switching power supplies for home use.
When you stop and think about what similar amateur type gear pre-built would cost you starting out with a nice pcb looks very attractive. The drill work is perfect and the silkscreen is perfect. Parts list is available and I think step by step assembly instruction might also be available as a pdf online. Little hints about forming the bends for some parts reminders about transformer's having polarity. It would ahve to be a HeathKit build to get any easier!
Since money does not grow on tree's and bipolar transistor amp pcb's are not falling from the heavens like mana I thought I would point it out!
I am going to use a tuning pcb's designed by someone else. I am just going to work the calculator and work the soldiering iron. If you stick to Brian's design you really only need to know how to solder, follow directions and read a VOM and have basic assembly skills like being able to measure and draw a straight line and work a drill and maybe a tap and die set if you want to get carried away.
I hope this was at least interesting and maybe helpful!
If I can find some classes not 2 hours away I want to take the test and get my ticket punched. In the mean time I am just sitting on the parts. I think he has been selling them from $10-$17 with the higher prices including free shipping I think and the lower prices having separate shipping but do not quote me. You could combine as many 2 transistor boards as you like for home or mobile use. Since they are bipolar's you have a lot of options with some of the Chinese options getting pretty good ok decent! You would have to ask Brian if the board's construction can sustain 28V continuous if it can with the right parts obviously than maybe it could be reworked for MRF150 since I think the case for the 28V MRF150 LDMOS is the same as the MRF421 and the 2SC2879 etc....Also the MRF421 which is bipolar can take up to what 28V again the rest of the parts would have to be able to live under those conditions but something to think about. I am thinking about that myself. Not every day you see a true class AB biased bipolar amp with SWR and thermal over load protection etc...that can live a long happy life at 24 volts! LOL It is not at all hard to find 24, 28, 32 and 50 volt switching power supplies for home use.
When you stop and think about what similar amateur type gear pre-built would cost you starting out with a nice pcb looks very attractive. The drill work is perfect and the silkscreen is perfect. Parts list is available and I think step by step assembly instruction might also be available as a pdf online. Little hints about forming the bends for some parts reminders about transformer's having polarity. It would ahve to be a HeathKit build to get any easier!
Since money does not grow on tree's and bipolar transistor amp pcb's are not falling from the heavens like mana I thought I would point it out!
I am going to use a tuning pcb's designed by someone else. I am just going to work the calculator and work the soldiering iron. If you stick to Brian's design you really only need to know how to solder, follow directions and read a VOM and have basic assembly skills like being able to measure and draw a straight line and work a drill and maybe a tap and die set if you want to get carried away.
I hope this was at least interesting and maybe helpful!
