Modifications for an SBE-34

[T23]

I have an SBE-34 coming in soon, got it for a great deal. Does anyone have any modifications for this transceiver?

1. Wanted to know what tubes I may be able to mod the final with? PL-509? 6146? Right now it should have pair of 6GB5 or pl500.

2. AGC modifications, the way the AGC is set up in this rig, you cant just add an S-Meter to the receiver.

3. Other mods?


T23

 

[Shockwave]

Because these tubes are grid driven, any small differences between the originals and replacements will cause noticeable changes in the input impedance. That requires an extensive alignment of the driver / pre-selector stages on all bands and some circuits may not have enough range to tune the new tubes without further modification.

When selecting a replacement tube you should pay attention to the inter element capacitances of the tubes and try to keep them close. None of these sweep tubes are made anymore so changing to another may not even be worth it. The only exception is the 6146B and the new ones made today are Chinese junk. That tube has shorter elements and lower internal capacitances too.

 

[T23]

How about russian 6p36s tubes? Those are said to be the equivalent.

 

[Shockwave]

How about russian 6p36s tubes? Those are said to be the equivalent.

That would be a good replacement tube since they share the same specs. Now if only you could buy the 6P35S for like $5 each new, that would be cool. Turns out you can at this link: 6P36S / EL500 / 6GB5 tube - POWER / OUTPUT tubes - Tubes-Store.com

 

[kc8adu]

rewire the heaters and use the 13gb5.
i bought a bunch for $2.50 ea.
stock the 2 are in series across 12v
so you have to connect them in paralel.