a quick question about ameritron 811hd

[DIGI MODE]

hello, i am looking at getting a ameritron 811hd and i would like to know what is a safe 100% duty cycle all day everyday power lever to have it at, for modes like sstv and am/fm ?

i am hoping for about 300 watts......is this doable ?

 

[Captain Kilowatt]

Straight from the Ameritron website.



Get the AL-811HD with 572B tubes
AL-811HD gives you the AL-811H with four 572B tubes installed. Get a higher power tank circuit and grid overload protection. Grid Overload Protection protects the tubes from excessive grid current due to mistuning and it protects against excessive drive power. Four 572B tubes give you more plate dissipation than a single 3-500Z tube. AL-811HD gives you 800 Watts output in SSB and 600 Watts for continuous duty in CW, RTTY, SSTVand AM operation.

I would run it a bit lighter than that just to be safe. 300 watts should be more than safe.

 

[BJ radionut]

Straight from the Ameritron website.



Get the AL-811HD with 572B tubes
AL-811HD gives you the AL-811H with four 572B tubes installed. Get a higher power tank circuit and grid overload protection. Grid Overload Protection protects the tubes from excessive grid current due to mistuning and it protects against excessive drive power. Four 572B tubes give you more plate dissipation than a single 3-500Z tube. AL-811HD gives you 800 Watts output in SSB and 600 Watts for continuous duty in CW, RTTY, SSTVand AM operation.

I would run it a bit lighter than that just to be safe. 300 watts should be more than safe.[/QUOTE

CK: Absolutly Correct! at 600w CDC even the 572B's will go into melt down....

DIGI: I suggest about 15-20w drive....Why? My AL-811 (w/572B's)(same PS as 811HD) with 25watts drive in CW easily outputs 450-600wts, depending on the band...
I do not consider CW (continuous duty) AM yes...IMHO 15wts drive MAX...1 minute ON/ 3 minutes OFF....and I use and extra fan to PULL air out of the case....
I don't care who says it!!! The cooling on the 811 series of amps in modes other than SSB....is totally lacking!!!
Unless you like purchasing tubes every few months $$$$
Enjoy Have FUN
All the Best
BJ

 

[Shockwave]

If the amp can make 800 watts pep on SSB, it can only produce 1/4 of that as AM carrier if you want to 100% modulate that carrier.

 

[DIGI MODE]

ok guys thank you very much for your input, all noted and understood

as my budget don't let me buy anything more than a 811hd at this time, it looks like 200 to 300 watts is about as far as i should take it. i have had many cb style brick amps in the past few years and i just end up blowing the guts out of them in sstv and other modes even when their rated at 350w+ and i am only using 100w in sstv and fm. it would be nice to be able to say sstv mode Scottie DX or maybe rebroadcast ARRL/RSGB news ect on 10m fm @ 300watts without popping something lol

thanks again all

73's