[Milsurplus] Sweep Tube Suggestions

[Thomas Adams]

At 19:42 13-05-13, Bruce Gentry wrote:

>After a quick look,  the 6LB6 and 6LR6/35LR6 both are rated for 990 
>volts supply on the plate. They are  big tubes, used extensively in 
>25 inch color consoles. They are too big to fit into most hybrid SSB 
>transceivers, so finding them might be realatively easy. I think 
>most larger sweep tubes would stand 1000 volts on the plate, there 
>are far higher pulses on them from the flyback, often over 5000 volts.
>Accidentally touching the plate cap on one of these operating in a 
>TV was extremely painful, leaving a serious burn, and could kill. 
>There were serious voltages and currents there. The downside of these tubes
>for audio or linear RF amplification is the design changes they 
>underwent in the mid 1970s. Even though not announced in the tube 
>manuals, the elements were often re-designed for a "snappy" turn 
>on-turn off to improve tube life and efficiency. They were helping 
>owners of 8-10 year old sets they paid $1200 for get one last hurrah 
>before replacing them.
>
>    Bruce, KA2IVY
>


For some reason, that just jogged my memory.

Some years back, a buddy of mine was into 4-1000A grounded grid 
amplifiers. Anyone who has ever
been there will tell you that the driving requirements for GG 4 by 1s 
are horrendous... his little Drake
transceiver wasn't cutting it.

SO, he took matters to the next level; a second power supply which 
fed the Drake finals ONLY.

I only have his word for it, but he claims that the sweep tubes in 
that poor Drake stood up to 1100 volts!
They didn't last very long, but he didn't care...   he was a TV 
repairman, and he just hit his tube caddy
every few weeks!

Suffice it to say that he GOT his needed driving power!


Mr. T.  W9LBB