I’ve just watched this video again, and I really appreciate it. I’ve just built a transmitter that seems to send “dots” well enough, but halfway through a dash the relatively clean signal turns into hash and my swr meter goes berserk. I will now try some of the remedies suggested in your video. Best wishes from New Zealand, Stephen Coote.
Good job, Peter. I have experimented with the BD139 too, and it's great for 7 MHz and 2 to 3W applications. Do you know of some other affordable and easy to obtain bipolar transistor for 7 MHz and 10-15W? Thanks!
hi Peter, great video! Thanks for sharing! I am designing a rig for 20 and 40m and I was wondering if a 2SC2078 transistor could suit as final amplifier stage as well...since it is much cheaper (about 1.20 EUR) than the 2n3553 (about 8 EUR). What is your opinion on that? Cheers, and 73 Roberto
With a little circuit modification, a 2SC2078 TO220 plastic CB final transistor should work very nicely. It will deliver more power with a 12V supply than a 2N3553 will too
I’ve just watched this video again, and I really appreciate it. I’ve just built a transmitter that seems to send “dots” well enough, but halfway through a dash the relatively clean signal turns into hash and my swr meter goes berserk. I will now try some of the remedies suggested in your video. Best wishes from New Zealand, Stephen Coote.
Just what I needed!
Thanks again Peter. This is very helpful.
Really enjoy your circuit walk-thrus and showing us how you reason through a circuit or design! Thanks So Much!
Do you have your drawing posted somewhere? It is hard to get an overall view from the video. Nice work! I like the debugging tips.
Good job, Peter. I have experimented with the BD139 too, and it's great for 7 MHz and 2 to 3W applications. Do you know of some other affordable and easy to obtain bipolar transistor for 7 MHz and 10-15W? Thanks!
You could try playing with the IRF520 fet they're pretty cheap. I succeeded in using an IRF530 on 27mhz
go to 1 to 40 mhz? IRF520 fet
Good video peter
i know it is kinda off topic but does anybody know of a good website to stream new movies online ?
@Bradley Cyrus I watch on flixzone. You can find it by googling =)
hi Peter,
great video! Thanks for sharing! I am designing a rig for 20 and 40m and I was wondering if a 2SC2078 transistor could suit as final amplifier stage as well...since it is much cheaper (about 1.20 EUR) than the 2n3553 (about 8 EUR).
What is your opinion on that?
Cheers, and 73
Roberto
Roberto - not sure - never used a 2SC2078.
With a little circuit modification, a 2SC2078 TO220 plastic CB final transistor should work very nicely. It will deliver more power with a 12V supply than a 2N3553 will too
Amazing video...thumbs up sir..
Can use this amp for beach 40 in dsb voice mode
No because it hasn't got any biasing on the final stage.