Hi,
looking for 2n3553 RDVV 1.5W notune schematic

There are two versions of it here listed as RDVV 1 Watt...

http://www.3-mtr.info/shareware/

I saw these, but they are "tune" versions

I'm looking for schematic of this one :
http://www.3-mtr.info/sales/RDVV%20NoTu ... %202007V1/

It is the scematic of the old 8W and the last part is of a BW 1Watt PLL board
The design is made by me in 2005-2006 and PKBee/rdvv made a new layout of it

RF-Head Thanks

Nice infos .anyone have a layout of an 25 to 30w no tune or easy tune one trimmer for 2sc1946a

Still got one of my original RDVV's I got from you RF HEAD back in 2005.

radium98 wrote: ↑Wed Oct 16, 2019 4:54 pm Nice infos .anyone have a layout of an 25 to 30w no tune or easy tune one trimmer for 2sc1946a

If it’s running on anything less than 15v it will need to be tuned for the frequency it’s on, because the output impedance of the final will be very low. Unless the “designer” is Paul Hollings and makes a mess of things because he has no idea what he’s doing, his 30w “no tune” is horribly inefficient and the current draw at 13.8v is insane.

There used to be a 20 Watt 13V8 "no-tune" amplifier made by one of the Italian companies. Current consumption was over 7 Amps - over 70 Watts was radiated as heat! If the two fans blowing on the huge heatsink failed, there was a 50 / 50 chance of the output transistor frying before the fuse blew.

no i mean a new old design

2n3553 5W for sure!

5W 2n3553

If you're very lucky you might get as much as 4 to 5w from a 2n3553 but it will get extremely hot at that power.

...I think about 2.5 to 3w is about as much as you should push those.

teckniqs wrote: ↑Fri Jun 26, 2020 8:35 pm If you're very lucky you might get as much as 4 to 5w from a 2n3553 but it will get extremely hot at that power.

...I think about 2.5 to 3w is about as much as you should push those.

depend of schematic to... do you try mrf237?

Yes and that would be much better for 5w but will still need very good cooling, a small clip on heatsink won't be good enough to cool it at 5w.
SD1127 is the same as MRF237 device, plus 2SC1947 is also very similar in performance,

teckniqs wrote: ↑Fri Jun 26, 2020 11:10 pm Yes and that would be much better for 5w but will still need very good cooling, a small clip on heatsink won't be good enough to cool it at 5w.
SD1127 is the same as MRF237 device, plus 2SC1947 is also very similar in performance,

i need 1.5-2w max but cool run as-possible

Why don't you run higher power device with <50% of its power.Maybe a RD06?

rigmo wrote: ↑Sun Jun 28, 2020 12:45 pm

i need 1.5-2w max but cool run as-possible

I would recommend the 2sc730 for this.