Thanks Carl, sorry for getting your name spelling wrong. I think I will
take your advice and see if I can get a medical pull, I see them from time
to time on eBay, unless you know of a better way to get the medical pulls.
I just want to keep a spare in case of fatal failure in a contest.
It looks like if you buy an amp from Ameritron they give you a choice 8877's
about 400 bucks cheaper for the import tube fitted.
Thanks again,
Mike
-----Original Message-----
Ive no experience with the Chinese version Mike but I believe that is what
Ameritron uses now and sells direct at a much lower price.
When needed for a job I stick with Eimac 3CPX or Y-xxx medical pulls of near
full output.
Carl
KM1H
----- Original Message -----
From: "Mike" <noddy1211@sbcglobal.net>
To: "'Amps Reflector'" <amps@contesting.com>
Sent: Thursday, July 24, 2008 10:04 PM
Subject: Re: [Amps] Fwd: Re: Bill Orr comment
>I know, just making a point that the tube will easily do more than 1500
> watts, as the other guy stated. I am more than happy having that tube
> running at 1200 watts and hopefully lasting for a few years that way.
>
> I am sure the IMD plots would look wonderful at 2600 watts SSB:-) I would
> be
> the only station on 17 meters.
>
> By the way Karl, I was going to buy a spare tube and I see some for sale
> for
> around 600 bucks, but they are imports, I guess Chinese, are they as good
> as
> my Eimac 8877 original?
>
> Mike
>
> -----Original Message-----
> From: Carl [mailto:km1h@jeremy.mv.com]
>
>
> Not unusual since it is seriously overdriven. Id love to see the IMD plot
> on
>
> SSB at the same power.
>
> Carl
> KM1H
>
>
>
> ----- Original Message -----
> From: "Mike" <noddy1211@sbcglobal.net>
> To: "'Amps Reflector'" <amps@contesting.com>
> Sent: Thursday, July 24, 2008 9:16 PM
> Subject: Re: [Amps] Fwd: Re: Bill Orr comment
>
>
>> My Al-1500 (8877) will do 2,600 watts into a dummy load key down on 17
>> meters with 100 watts of drive as measured on an LP-100.
>>
>> Mike
>>
>> -----Original Message-----
>>
>>
>> Bill Orr was hardly a quack. Very knowledgeable and nice guy, met him
>> several times over the years. An 8877 will get pretty darn close to 2 X.
>> It
>> was used in at least one 2.5 KW commercial FM transmitter that I know of
>> and
>>
>> by FCC rule the transmitter had to be capable of 110% rated power
>> (2750W).
>> And that is CCS!
>> 73's
>> Chuck
>> W6RD
>> ----- Original Message -----
>> From: <k9mk@flash.net>
>> To: "Commander John" <crazytvjohn@yahoo.com>; <amps@contesting.com>
>> Sent: Wednesday, July 23, 2008 11:01 AM
>> Subject: Re: [Amps] Fwd: Re: Bill Orr comment
>>
>>
>>>
>>> I can't speak to todays class of ceramic tubes but in the 70's I
>>> built
>>
>>> a number of 3-1000Z amps. The rule of thunb for a well designed AB amp
>>> was 2:1, output power vs. dissipation. So, yes I agree with the Orr's
>>> "rule of thumb" here. The 3-1000Z typically did 2:1 RF out 80m-15m but
>>> it
>>
>>> did require a well thought out RF deck. I will not name names here but
>>> I
>>> saw a dozens of what I call stressed 4-1000A amps that made it to the
>>> 2.5:1 ouput ratio.
>>>
>>> It is probably related to the manufacturers design but I have never
>>> seen 3KW from an 8877 or even 1600W from a 3CX800... Either something
>>> is
>>> being lost in translation or it kinda makes you wonder about the claims
>>> surrounding our modern ceramic tubes...
>>>
>>> 73's Mike K9MK/5
>>>
>>>
>>>
>>>
>>> -------------- Original message from Commander John
>>> <crazytvjohn@yahoo.com>: --------------
>>>
>>>
>>>>
>>>> Commander John wrote: Date: Wed, 23 Jul 2008 10:23:38
>>>> -0700 (PDT)
>>>> From: Commander John
>>>> Subject: Re: [Amps] Bill Orr comment
>>>> To: Peter Voelpel
>>>>
>>>> Who is this "quack" guru?
>>>> john w9zy
>>>>
>>>>
>>>> ~~~~~~~~~~~~~~~~~~~~w9zy
>>>>
>>>> Peter Voelpel wrote:
>>>> 2-2.5 times the dissipation is normal.
>>>> Assume 1500 out, at 70% efficiency that is 643W dissipation,
>>>> 1500/643=2.33.
>>>> Eimac claims 75% efficiency on their 3CX3000A7 datasheet in AB2.
>>>>
>>>> 73
>>>> Peter
>>>>
>>>> -----Original Message-----
>>>> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]
>>>> On
>>>> Behalf Of Gudguyham@aol.com
>>>> Sent: Mittwoch, 23. Juli 2008 18:30
>>>> To: amps@contesting.com
>>>> Subject: [Amps] Bill Orr comment
>>>>
>>>> I was reading the Bill Orr handbook and on his section about amplifiers
>>>> he
>>>> says.....A properly designed grounded grid amplifier should produce 2
>>>> to
>>>> 2.5
>>>> times the plate dissapation of the tube in output. He did not put any
>>>> limitations on the statement as to IMD or anything like that. He did
>>>> not
>>>> say if the tubes ratings would be surpassed (I am sure they would), but
>>>> I
>>>> think what he was saying is that the tube should continue to make power
>>>> to 2
>>>> to 2.5 times it's dissapation before it would not make any more power
>>>> and
>>>> flatten out.
>>>>
>>>> Upon speaking with an amp "Guru" about this subject, he procalimed that
>>>> Bill Orr was a "QUACK". The basis of his claim was that he was never
>>>> able
>>>> to build an amplifier that obtained that kind of results.
>>>> What say you? Lou W1QJ
>>>>
>>>>
>>>>
>>>> **************Get fantasy football with free live scoring. Sign up for
>>>> FanHouse Fantasy Football today.
>>>> (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020)
>>>> _______________________________________________
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>>>>
>>>> _______________________________________________
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>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> W9ZY
>>>> .... Commander John ....
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> W9ZY
>>>> .... Commander John ....
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
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