Thanks Stefan, I will buy a few using FKP1 caps, hopefully that will do the trick. What is the VDC rating of the FKP1 caps in your 1 kW PA? Output impedance is about 1.4 ohm. I have designed it to pr
The simulator tells me that the peak to peak current across the FET (at 200 W output) is about 24 A. Long way from 55 A, so we should be fine. When /p, I will be probably using a single 12 V battery
Hello LF group, I am building a 200 W Class-E transmitter for LF but keep killing the capacitors in the output circuit (both C1 and C2 according to the schematic in Sokal's QST article). I have used
Well, that's why I thought the monster IXYS FET I used, which is obviously an overkill, will probably be hard to kill. I can't possibly exceed the 55 A current limit (it's fused to much less than th
Hi Alan, I am also using a simulator, the free LTSPICE which seems to work OK, in fact I use it with wine under linux. With this, it is easy to predict the voltages that will develop across all compo
Hi Alan, thanks for the tip, I will keep an eye open for RIFA PHE428 or PHE450 which seems to be the newer version of that capacitor type. In my PA, I used two .1 uF caps in series to make .05 uF, th
Hi Stefan, Things haven't been much better over here, for the past couple of days... http://people.physics.anu.edu.au/~dxt103/grabber/ 73, Dimitris VK1SV
I have written up my experience building this Class-E PA for LF here: http://people.physics.anu.edu.au/~dxt103/class-e/ Maybe other beginner LF operators will find this useful. 73, Dimtris VK1SV
Hello Stefan, oh how I miss Europe and the high amateur radio operator density of that place! Over here, I think, the best operator active on LF/MF meeting consisted of four people earlier this year
Hello Hideho, Thank you for the tip. Do you know how long is JA7NI is planning to transmit? Over here we have another at least four hours to sunset. 73, Dimitris VK1SV
Hi Rick, that is a handy site. As suggested by John and others, this signal could be JA7NI. He has a very good antenna and he has reached my grabber many times in the past. 73, Dimitris
Hello group, I don't get to see many traces in my grabber so naturally I am quite excited when this happens. Who will claim this partial DFCW trace that appeared in my grabber this morning at sunrise
Hello Marcelo, just a thought, why not transmit on two adjacent frequencies that fit in a single grabber window? My grabber is currently setup around 137780 Hz. 73, Dimitris VK1SV
By the way, here is my current 40 m 807 transmitter.This was the first attempt at building a valve TX. people.physics.anu.edu.au/~dxt103/valves/807/ I will use the same type of chassis for the 472 kc
Hi Stefan, I am also not part of the tube generation (born in the seventies) but I am fascinated by them! While a class-E PA is a very sensible and efficient PA, tubes (or valves) have a different ki
Well, yes. There are builders and there are users I think. If you enjoy building, you spend most of your time doing that.If you enjoy operating, you do only the minimum necessary building. The valve
Hello lf group, has anyone made or thought of making a 472 kc transmitter using vintage FT-241A xtals? I have three or four of these with fundamental frequencies in the 474 kc to 479 kc range, so I w
I am glad you found the eBay seller and your project is about to be revived. A VFO, as David G4DMP mentioned before, is also another valid option. It shouldn't be too hard to make a VFO stable enough
