Sb 200 Conversion To Ceramic Tube

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Sb 200 conversion to ceramic tube.

A good compromise is to be found for the 10 12 15 and 17 m bands. Install heathkit sb 220 hv transformer 4. Here is a summary. Replace 4 572b tubes with 2 gi 7b tubes 2.

If you are performing the low power conversion reconnect the wire to the 160 volt tap on the rectifier board. The project started as a retrofit of the clipperton with gi 7b tubes. Sb 200 six meter conversion and retrofit n4lr and w4zt 6 2007 in progress heathkit sb 230 please note. G neutralization capacitor a new 390 pf 1kv mica capacitor is installed on the driver s.

Modern production methods as well as continuous in process. It is normal to get 100 to 150 watts less on 10 meters than 40 meters due to inherent amplifier design issues. Over 1 000 0 5 x length mm. 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.

This statement is valid for both the sb 200 and sb 201. Replace power supply diode cap board with far circuits board and new smaller caps 3. It made its debut in 1965 and covered the 80m 10m bands available at that time. However the more i worked on it the more changes i made.

Camber the standard camber of ceramic tubes in accordance with din 40 680 is a value of 0 5 of the total length. Tighter tolerances are subject to individual agreement. The straight forward grounded grid design using two 572b triodes has stood the test of time fairly well. If you adjust for a 15 m swr of 1 2 it will be 1 7 on 17.

If all looks well install the new 6883b or 6146b pa tubes and close up the sheet metal shields. Ceramtec s standard tolerances for unground ceramic tubes mm. The heath sb 200 was introduced in 1964 and sold in that year for 200. They can handle the 100 w drive without problems.

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. Using 100 pf ceramic trimmers makes things easier. For the high power conversion this lead will be connected later. My sb 200 amplifier with cetron 572bs uses the circuit of fig e with 1 1 5 nf per valve.