HI. i have constructed this linear amplifier 500w rms (2kw pep) (50ohm) with 12 mosfet irfp360, http://tzitzikas.webs.com/linear500w.jpg for 160m band. When i gave 3watts of driving r.f power, it gav
HI sasas asasas: I have been looking at this schematic all week. I don't get the "500w rms - 2 kW PEP" thing, that doesn't make sense to me. RMS isn't that different from average and 2 kW PEP is abou
i mesured the r.f power with digital power/swr meter and it was only 190 W at 106VDC (6A current). The manufacter claims that at 500w output r.f power, at 110vdc, the current is 13A. So, the efficie
It is quite normal for an amplifier to show lower efficiency when it is run at lower drive and output levels. As the drive is reduced, the class of operation moves in the direction of class A and we
what do you mean with the phrase: <<The device substitution has possibly reduced the amplifier's gain and efficiency.>> . thank you -- http://tzitzikas.site90.net (tzitzikas site) http://forum.tzitzi
You might consider imbalance in each side of the primary which will cause a net dc to pass, saturation and over-heating. This may be rubbish but it could get others thinking along a different path. D
ORIGINAL MESSAGE: REPLY: Also, there is some wiggle room when specifying PEP without specifying duty cycle. RMS is a constant but PEP can be anything. 73, Bill W6WRT _________________________________
And how can i repair this problem??? You might consider imbalance in each side of the primary which will cause a net dc to pass, saturation and over-heating. This may be rubbish but it could get oth
This definition dates from AM times with "plate" modulation. The modulation system allowed the supply voltage to vary from 0 for 0% instantaneous modulation o twice the supply voltage (four time inst
You get about 18 dB power gain out of it which is quite right for a FET amplifier of this kind. The problem lies most likely with the transformer itself: the 43 material in the core is optimized for
hI, AND THANK FOR YOU ANSWER. DO YOU HAVE TO PROPOSE ANY PROPER MATERIAL OF FERRITE CORES FOR FREQUENCES 1-2MHZ? I saw AMIDON'S SITE: https://www.amidoncorp.com/categories/9 and i think 31 material i
I've looked again at the jpg and I think you have used trifilar windings, so, that's my first idea more or less gone. Imbalance can be due to poor coupling between the windings themselves or imbalanc
Some additional photos from my linear: http://tzitzikas.webs.com/fet20.JPG http://tzitzikas.webs.com/linear20.JPG http://tzitzikas.webs.com/linear21.JPG http://tzitzikas.webs.com/linear22.JPG http://
I see you are using hex socket screws. It is very easy to over-tighten screws to fix plastic devices to a heatsink, I've seen them crack after a little time in the field due to expansion and contract
hi. i am not use insulators between mosfet and heatsink in order to have the minimum thermal resistance. I am using only silicon thermal conductive paste to decrease the thermal resistance. So, the h
Are you using the same manufacturer as your friends? If so, yours should be the similar performance unless something is wrong. David hi. i am not use insulators between mosfet and heatsink in order t
Hi sasas asasas: I haven't found the detail of this amplifier yet, was this amplifier designed for 160 meter at the same gain and efficiency as the other bands? Did you test the gain and efficiency a
The linear have been constructed by me (if you mean the manufacter of linear amplifier). The prototype have been constructed by schematic designer and you can see a photo here: http://www.tzitzikas.w
Hi. All of my instruments are ok. This linear is only for 160m band and for bellow frequences (for tests only in dummy load). I have not test it at higher frequences and my pll exciter works maximum