Hi Andy... me again... I was so curious to see what could happen thatI had a very quick dinner and connected all, but... now the output xfmr has 7T/19T here my readings/calculations: (see attached pi
Andy.. you are almost better than online help desks :-D yes the guard circuit is on place but no current is flowing toward the PA, testing disconnetting it needs just to warm up the iron ;-) the PS s
anybody has good ideas for a replacement hobby?? fishing? growing flowers? Andy: the suggestion of try without the guard circuit revealed that some effects in this area are present. I left the guard
that was also my thought.. but they run at room temperature: the resonance is obtained with 4 polyesther 2200 pF 2000 Vdc caps. the classic boxes 25x15x5mm Marco If the conditions change as the PA is
Hi Johan, you know if the frequency goes up, the wavelenght becomes smaller therefore the peaks are closer and closer so µwave are very similar to DC ;-) Marcus, do you mean pick the stereo and organ
now my thoughts are even more confused.... Hi Andy, me again.... after a long night of meditation, I remembered I had a bounch of old style mica capacitators 1000pF 1000V.. I put 9 of them in paralle
Hi Alan, and thanks for joining :-) it's hard to believe at this stage that is correct to speak of "high currents".. The PA is an half bridge like Andy's 700W but now I'm testing at low voltage: I se
Hello Chris, yes I'm testing into a dummy load and getting troubles trepassing the 15kmW (thousend of mW) limit!!! I drive with a reasonable waveform both the qrp TX and medium power TX (and now the
Hi Stefan :-)))) soon Paul will ask for a bandplan: it is becoming so crowded there! sms from both sides of the ponds hihi I fear to think what people who live in the last floor of my building if the
Hi Alan, Andy, Chris, I replaced the caps in the output LC with WIMA FKP1, the 2 caps wich replaces the missing half of the bridge are still Cornell Dubillier 940C serie (rated at 9A @100kHz), so now
Hi Stefan, and thank you :-) so you have too something to mumble while sending VLF SMS ;-) There is nothing really new.. I started from an avalable chassis with on board a PS giving 180Vdc (1200W) an
Hi Andy, and again thank you for the time and analythics :-) this give me something to do in the rest of the weekend ;-) Let me just point a couple of point, but will duly verify all the suggestions.
Thank you Marcus: haahaa also you kept in council :-) After fighting to place the oscillo probes on the gates which are a bit hidden... (this could be an improvement area...) the square wave is swing
mmmmmmm Thanks Markus, Alan, Andy: I found something that unfortunately needs to unbild some parts before to change and hopefully fix... After check of the dummyload, directionalcoupler, attenuator a
Good morning LF &VLF :-) I had not a big choice among available cores for the driver xfmr.. and finally I choose a BN43-202 with a lower AL but higher cross section. Now the driver xfmr is wound 10T
mmmmmmm Thanks Markus, Alan, Andy: I found something that unfortunately needs to unbild some parts before to change and hopefully fix... After check of the dummyload, directionalcoupler, attenuator a
...probably the previous message is missed somewhere... Nuntio vobis gaudium magnum!!! After replacing the driver xfmr with a new one wound on a BN43-202 core (not the best but the only available her
heyheyhey.. now I'm testing with the new coil still at 50Vdc ;-) ops I was forgetting: without dissipator :-)) just with the mounting alu block it runs at room temp, maybe it is worth later at full p
Thank you Andy :-) now by the first I have to find a way to fix the coil (which is quite bulky..) I used 2 corks :-)) and hotmelt glue, but after 1 hour of testing the coil falled :-((( looking on th
Hi Stefan, and thank you for effort and suggestion :-) Indeed carefully checking while testing I found what was going wrong beyond 30Vdd of supply to FETs: the xfmr between the IXDD stage and gates b
