-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
Transistor help
- Thread starter KJ4BAE
- Start date
Toll_Free
Well-Known Member
If it's the stud mount devices, tell your friend to buy another amplifier... Seriously, those things are SPENSIVE when ya can find them.
If it's standard flange mount, then call RF Parts. RF Parts Company Amateur Radio Catalog They can tell you which devices from their SRF line will cross reference. Typically you see 10-25 percent more Pout with the RF Parts devices. If it has no negative feedback, I'd order their kit as well, to prevent the new high gain devices from launching into oscillation.
--Toll_Free
If it's standard flange mount, then call RF Parts. RF Parts Company Amateur Radio Catalog They can tell you which devices from their SRF line will cross reference. Typically you see 10-25 percent more Pout with the RF Parts devices. If it has no negative feedback, I'd order their kit as well, to prevent the new high gain devices from launching into oscillation.
--Toll_Free
I think that CTC transistor has the larger of the two flange mount cases. Most of the transistors that have the closest specs to the original part have been discontinued and their price is well beyond their value. The reason behind this is that those transistors are obsolete. I believe one of the closest common transistors available today would be the 2SC2290. This transistor will have a lower input and output impedance then the original.
This means to get the full power from the transistor one would have to make slight modifications to the wraps on the transformers or change the values of the caps used on them. The good news is even without any modification the amp will work well just installing the 2SC2290 transistors. It will most likely make more power then stock but with slightly less efficiency. The larger transistors will handle the dissipation so long as you don't go crazy with the drive.
This means to get the full power from the transistor one would have to make slight modifications to the wraps on the transformers or change the values of the caps used on them. The good news is even without any modification the amp will work well just installing the 2SC2290 transistors. It will most likely make more power then stock but with slightly less efficiency. The larger transistors will handle the dissipation so long as you don't go crazy with the drive.
2sc2290,s are near $130 for just 1 on rf parts.
Expensive yes but mutch better than all these mosfet amps they make now days
Expensive yes but mutch better than all these mosfet amps they make now days
HG makes a replacement version of the 2290 that is much lower in price. I would still try to double check what the closest final would be to that original part.
Here is a nice video on this amp.