Should a 250th tube have color under load in Bc-610

[K1YTG]

I have read that 4-250's and 4-400's should be run with some color on the plate when under load.  Is that also true for a 250th? 
It gets rather bright red when the current is high as when not dipped to resonance.  The color goes away mostly at resonance.  Is it best to avoid color on the plate of this tube?
Thanks, Norm

[KB4QAA]

http://tubedata.tubes.se/sheets/088/2/250TH.pdf
Have you looked at the tube manual?

It does say the plate is a visible red at the maximum dissipation of 250 watts.  Installation notes state that heat dissipating connectors must be used on the plate and grid connections.

[K1YTG]

The BC-610 does not have heat dissipating connectors on the grid or plate.  And no fan.  I guess I would have to run it at less than 250 watts dissipation for this set up.
Norm

[G3RZP]

I wouls suggest that fitting heat dissipating connectors should be a priority, seeing that new or good 250TH tubes are getting rare.

[WB4IUY]

I know this is an old topic, but I've got a new 250th in my collection and nothing to run it in. If someone needs it, drop me an email to wb4iuy @ teara . org

[K8AXW]

If this is an unmodified BC-610, run it at specs.  The only concern is excessive tube color.  If at resonance and full output, the tube color all but disappears, forget it. 

The BC-610 was without a doubt (in my opinion anyway) was the biggest, heaviest transmitter ever built for military work.  I think the expression, "built like a battleship" originated with the 610!

[KC4MOP]

If this is an unmodified BC-610, run it at specs.  The only concern is excessive tube color.  If at resonance and full output, the tube color all but disappears, forget it. 

The BC-610 was without a doubt (in my opinion anyway) was the biggest, heaviest transmitter ever built for military work.  I think the expression, "built like a battleship" originated with the 610!

The T368 was another military monster.

[K8AXW]

Never heard of the T368.  Tell me about it.

[KE7TRP]

Here is my T368C transmitter

http://youtu.be/WC4B2bsyz5w

500 watts OUTPUT AM carrier.  Freq is from BC band up to about 21MHZ.

Oh and yes, there will be some color on the 250 tube under full load.  No need for fans for heat connectors.  They where built to run and run constant.

C

[K8AXW]

TRP:  Many thanks for posting the your video on the T368C transmitter.  I've never heard of that one.  Very impressive. 

My eyes were also drawn to the R-390 and the SP-600.  Our unit was the first, or one of the first to use the R-390.  We were told at the time (1955-56 - Forget the exact year) the R-390 cost about $2500 1956 dollars, which was over twice the cost of our other top of the line receivers made by Hallicrafters and Hammarlund.

The SP-600 was our choice (DL4TPO and DL4RK) for ham radio work.  You can see ours on QRZ.com, K8AXW.  We tried several top of the line receivers including one of the 75A series from Collins before settling on the SP-600.  We had other ham stations on the same post and several of them used the SP-600 as well.