In a message dated 11/22/04 7:56:07 PM, [EMAIL PROTECTED] writes:
> One thinks of MANY sweep tubes rated for so-called Pdiss of 16
> watts and 20 watts that are regularly run at hundreds of watts of
> RF! The tubes don't seem to melt.
>
> I think of the ubiquitous 6JS6C with a rating of 30 watt
Sweep tubes are a little different animal. They are designed for high
peak power levels in TV sweep circuits. SSB has a pretty high peak to
average power level. The average power is only in the order of 10 to 20%
of pep. Unless you run heavy processing and then the sweep tubes will
take a dive.
I need it!
Gary
Jim Wilhite <[EMAIL PROTECTED]> wrote:
Hello All:
Does anyone need a manual copy of a Heath SB 620? I have a copy of most of it.
The manual covers the 455 KC IF frequency complete with diagrams and build
information.
This is a good clear copy for cost of 5 bucks mailed in the U
Gary,
I like your analysis on the topic. Brian may be looking for hard data to
back up the theoretical. I recently finished a single EL-34 (6CA7) Class AB2
RF linear amplifier in a Central electronics 20a. In my case I got only 20%
efficiency on AM! I am going to present some data ac
Hi Brian:
Consider what the efficiency is with no drive. The tube is drawing
current and has voltage therefore it has input power but no output.
Efficiency is 0%.
As input drive is applied the efficiency increases but so does the plate
current. The trick is to reach the 25% power point (or 50 Vo
Aren't there a lot of commercially built amateur radio linear
amplifiers and RF finals that exceeded he manufacturers MAX
Pdiss rathings over the years, by adding a COOLING FAN to take
away the extra heat?
One thinks of MANY sweep tubes rated for so-called Pdiss of 16
watts and 20 watts that a
On 22 Nov 2004 at 22:23, Gary Schafer wrote:
> Brian,
>
> What he is saying is: you need to have the 811A tuned up at 200 watts
> output on cw or pep for a 50 watt carrier out. (pep is 4 times carrier)
AH ha - I thought we were talking INPUT.
For 50 watts per tube to this Quad 811A amplifier,
I've got to get in on this HIHI.
Some readers may not fully understand what you guys or talking
about.
So I will try to confuse it all some more. HIHI
Plate dissipation is the heat that the plate of a tube is
emitting.
The manufacture of the tube has what is known as max plate dis
I don't know, I never had any linear amps.
I suppose you can run them as high as you like provided:
The plate dissipation is not exceeded (ccs45 watts, icas 65 watts per tube),
The modulation peaks don't get cut off,
The power supply can take the constant current and peaks.
The actual class of
Brian,
What he is saying is: you need to have the 811A tuned up at 200 watts
output on cw or pep for a 50 watt carrier out. (pep is 4 times carrier)
When you tune up you tune it for max output at the 200 watt level with
full drive. At that tune setting the tube will be around 60% efficient.
On 22 Nov 2004 at 20:23, [EMAIL PROTECTED] wrote:
> Going to shorten it's life considerably.
Theoretically maybe. Have you tried it. How can you know
for sure? Theory says a bumble bee can't fly. My 811A tubes
never burned up.
Where did you get your 30% number from? Who transmits
their AM w
On 22 Nov 2004 at 20:23, [EMAIL PROTECTED] wrote:
> Going to shorten it's life considerably.
Theoretically maybe. Have you tried it. How can you know
for sure? Theory says a bumble bee can't fly. My 811A tubes
never burned up.
> To properly adjust a linear amp for AM it is necessary to tune
Hello All:
Does anyone need a manual copy of a Heath SB 620? I have a copy of most of it.
The manual covers the 455 KC IF frequency complete with diagrams and build
information.
This is a good clear copy for cost of 5 bucks mailed in the US. First person
to email me gets it.
73 Jim
W5JO
On 22 Nov 2004 at 8:29, Brett gazdzinski wrote:
> Hu,
> How many 811a's in that amp?
>
> If 4, then I think the 811a has 65 watts of plate dissipation, 4x65=260.
> Cut 260 watts in half for 130 watts of carrier output, but I doubt I
> would
> run them
> that hard. The power supply likely wont
Hi Don
I am needing a jw miller 455 kc if can part # 12-c30 or khz-455 or merit #
BC-352 or stancor RTC-8632
any help?
thanks
Dean
KA6BGW
For Sale: Vintage Radio Literature. Media Mailing cost additional.
ARC-5 Bench Test & Alignment Procedure, clean copy with fold-outs. $7
Electric Radio #99, July 1997. $1
RCA Receiving Tube Manual RC-20, 1960. Excellent. Looks almost new. $12
RCA Transmitting Tube Manual TT-5, 1962. Looks exce
Hu,
How many 811a's in that amp?
If 4, then I think the 811a has 65 watts of plate dissipation, 4x65=260.
Cut 260 watts in half for 130 watts of carrier output, but I doubt I would
run them
that hard. The power supply likely wont take that much abuse, its designed
for
ssb service, very low dut
Ralph Rote:
> ... what are some operationa guidelines as regards i/p and o/p power, duty
cycle, cooling etc.
Ralph, ultimately what you're looking for is to run the amp at 1/4 the
maximum CW output of the amp. In other words, if the amp runs 800 W output
on CW you want to drive it to only 200 W o
Ralph,
A good rule of thumb to follow is simply this: the maximum carrier output
you're going to safely get out of your separate linear amplifier is limited
to HALF of the plate dissipation of your linear's tube(s)...
Example: I sometimes drive my HB 2 x 813 as a linear for AM. Each tube has a
pl
Hi all,
I feel this subject must have been covered many times but I just can't find it.
Specifically, I have a Heathkit HX-10 Marauder driving an Ameritron AL-811H
on CW and SSB and would also like to try it on AM. The driving power on AM
is 25 watts.
Is this a correct use of the amplifuer and i
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