GS-35b Russian tube chimney/fan system fits Heathkit SB220 3-500Z 3CX1500 KK4NO

Description

Parts to properly cool a Russian GS-35b triode in a Heathkit SB220 modification. Should work fine in your custom applications as well.
120v fan rated 140 cubic feet per minute cools to 133 cfm thru the chimney. Comfortably over the 88 cfm needed to cool the tube properly. Nice and quiet too.
Custom made silicone hoses and hardware shown included in the kit.  The red 90 degree hose replaces the straight hose if you want to exhaust to the side or up.
The 90 degree red hose is not included in the kit. Zap me a message if you want the 90 degree red hose.
The Heathkit 3-500Z filament is 5 volt.  Russian tube is 12.6 volt 3 amp.  I have added two small transformers under chassis to boost the 5 volts filament supply voltage.
They are Hammond 164H16 from Digikey. You need two transformers.
You still get 120/240 operation. Phasing is tricky.
Add a series 1 ohm 10w aluminum resistor.
I have paralleled an 8 ohm 15 watt speaker Lpad  It is 0-4 ohm to parallel the 1 ohm for filament adjustment.
The input tuning is done by microprocessor and relays switching in coils and capacitors.  It is automatic at SWR above 1.3.
Band select is using relays, not fully tested.
The plate transformer must be delayed by 90 seconds for warmup.  HV filters are above original capacitance. I have 30a relay driving two thermistors to combat surge.
This mod is operational on 80m. Tube saturates at 35W drive.  Bias around 12-13 volts for 200 mils plate.  Bias cutoff of modded W7RY board 43V.  Tube not included in the sale.
The chimney and fan should work great for you. Simple with these custom made parts.
Thanks for looking and 73.