4-400A vs 4-400C and Viking Thunderbolt

[wa2dtw]

Have been trying to find specifics on 4-400C.  Does anyone know if it is completely interchangeable with the 4-400A?   Can a 4-400A be used together (in parallel) with a 4-400C in the Thunderbolt?


Thanks and 73
Steve WA2DTW

[Pete, WA2CWA]

4-400C/6775 Specs:
http://catalog.rell.com/rellecom/scripts/SkuPage.asp?SKU=8472&PNO=&PNM=

4-400A/8438 Specs:
http://catalog.rell.com/rellecom/scripts/SkuPage.asp?SKU=8467&PNO=&PNM=

[wa2dtw]

Many thanks, Pete
They seem exactly the same to me.

73
Steve WA2DTW

[Todd, KA1KAQ]

My recollection Steve, is that the 4-400C was better for heat dissipation or something along those lines. Nothing more. Of course, I have no idea where I read or heard it...

[WBear2GCR]

isn't the C a carbon plate?
the A metal plate...

hard to burn through the carbon plate... if one was doing such a thing...

             _-_-WBear2GCR

[k7yoo]

The later Eimac 4-400 (C) tubes had the plate that looks like corrugated tin roofing. The earlier 4-400's had the gear tooth look plate. I always look for the later corrugated style. The later "brand X" and current production stuff is all totally different and varies from the Amperex with the grahite do-nuts to the current straight graphite oriental tubes. I have used all of these with OK results. The oddballs were the Penta-Labs from Sta Barbara CA. These tubes always seemed to have higher emission than the Eimacs but have been out of production for so long that they are rarely seen in good shape. DO NOT confuse these with the current Penta brands--these are imports.