A good compromise is to be found for the 10 12 15 and 17 m bands.
Sb 200 conversion to ceramic tube.
The project started as a retrofit of the clipperton with gi 7b tubes.
This statement is valid for both the sb 200 and sb 201.
Enjoy the videos and music you love upload original content and share it all with friends family and the world on youtube.
My sb 200 amplifier with cetron 572bs uses the circuit of fig e with 1 1 5 nf per valve.
Sb 200 six meter conversion and retrofit n4lr and w4zt 6 2007 in progress heathkit sb 230 please note.
Modern production methods as well as continuous in process.
If it exceeds this loss on 10 and 15 meters check the parasitic choke resistors before the amplifier starts to oscillate and arcs destroy your plate tuning capacitor or band switch.
The heath sb 200 was introduced in 1964 and sold in that year for 200.
However the more i worked on it the more changes i made.
Install heathkit sb 220 hv transformer 4.
The sb 200 from heathkit is a 1200w pep input linear amplifier which will develop an output of approximately 600w pep when operated on a 120vac line.
Tighter tolerances are subject to individual agreement.
Camber the standard camber of ceramic tubes in accordance with din 40 680 is a value of 0 5 of the total length.
Over 1 000 0 5 x length mm.
G neutralization capacitor a new 390 pf 1kv mica capacitor is installed on the driver s.
Using 100 pf ceramic trimmers makes things easier.
If you are performing the low power conversion reconnect the wire to the 160 volt tap on the rectifier board.
For the high power conversion this lead will be connected later.
If all looks well install the new 6883b or 6146b pa tubes and close up the sheet metal shields.
They can handle the 100 w drive without problems.
It is normal to get 100 to 150 watts less on 10 meters than 40 meters due to inherent amplifier design issues.
Here is a summary.
Replace 4 572b tubes with 2 gi 7b tubes 2.
The straight forward grounded grid design using two 572b triodes has stood the test of time fairly well.
Ceramtec s standard tolerances for unground ceramic tubes mm.
Replace power supply diode cap board with far circuits board and new smaller caps 3.
It was last produced in 1978 when the sb 201 was introduced without 10 meter capability due to the fcc laws governing the manufacture of linear amplifiers for that frequency range.
Reinstall the regulator board.