[Amps] What is this amp set up for

Tue Mar 25 08:48:53 EDT 2008

Oh, OK.

Several amps did that including the LK-800TNY and the 44 MHz version which 
both ran the LK-550 transformer.

Ive redone a few of the latter for the 6M EME crowd.

Carl
KM1H

----- Original Message ----- 
From: "Roger (K8RI)" <sub1 at rogerhalstead.com>
To: "jeremy-ca" <km1h at jeremy.mv.com>
Cc: "Bill Fuqua" <wlfuqu00 at uky.edu>; "Amps" <amps at contesting.com>
Sent: Tuesday, March 25, 2008 2:52 AM
Subject: Re: [Amps] What is this amp set up for

> jeremy-ca wrote:
>>
>> Huh? What is that supposed to mean? They either have the 3CX800 or the 
>> CPX installed (or a Y version). Im not aware of any commercial ham amp 
>> that is pulse rated.
>>
> IIRC for a while Henry listed a either a 2002A or 3002A as a legal limit 
> amp.  I think it was on 6-meters and ran a 3CPX800.  It wasn't rated for 
> pulse, but it did have take advantage of the extra cathode emission 
> available.
>
> Roger (K8RI)
>
>> Carl
>> KM1H
>>
>>
>>
>>>
>>>
>>> 73
>>>
>>> Roger (K8RI)
>>>>
>>>> They must provide extreme levels of linearity in medical service and 
>>>> are conservatively operated. In amateur service they are known for 
>>>> ruggedness and superb linearity.
>>>>
>>>> Bandwidth has nothing to do with it.
>>>>
>>>> Carl
>>>> KM1H
>>>>
>>>>
>>>>
>>>> ----- Original Message ----- From: "Bill Fuqua" <wlfuqu00 at uky.edu>
>>>> To: "jeremy-ca" <km1h at jeremy.mv.com>; "Roger (K8RI)" 
>>>> <sub1 at rogerhalstead.com>
>>>> Cc: "Amps" <amps at contesting.com>
>>>> Sent: Monday, March 24, 2008 11:59 AM
>>>> Subject: Re: [Amps] What is this amp set up for
>>>>
>>>>
>>>>> I have gotten several 200 MHz power pulsed amplifiers from University 
>>>>> surplus sales.
>>>>> These were used in MRI systems. One interesting one had a version of 
>>>>> the 8877 with out
>>>>> fins clamped in a 1/4 wave cavity. It had a solid state driver 
>>>>> amplifier that was also pulse rated.
>>>>> I think a hint may be the spec.  of 200 MHz plus or minus a few MHz 
>>>>> and a 2kW pulse rating for
>>>>> power.  Pulse operation is usually not used in amateur work due to the 
>>>>> wide band width.
>>>>>
>>>>> 73
>>>>> Bill wa4lav
>>>>>
>>>>>
>>>>> At 08:52 AM 3/23/2008 -0400, jeremy-ca wrote:
>>>>>> With 2M amps being not that uncommon the price is usually lower.
>>>>>>
>>>>>> With the only 222 amps being custom made or modified as that one they 
>>>>>> tend
>>>>>> to be more in demand. And you know what happens on Ebay when the 
>>>>>> frenzy
>>>>>> starts.
>>>>>>
>>>>>> Those holes look to be for extra air flow thru the cover after it got 
>>>>>> hot
>>>>>> and deformed. I'd open it all the way and install a silicon rubber 
>>>>>> chimney
>>>>>> with a non restrictive mesh on top. I had to do that with my 144 and 
>>>>>> 222
>>>>>> amps; made a huge difference and no more tuning drift.
>>>>>>
>>>>>> Prices are even higher for a good 432 amp in the 8938 and 2x 3CX800
>>>>>> category.
>>>>>> I gave up finding a 8938 at a good price and wound up rebuilding a 
>>>>>> Collins
>>>>>> USAF 350 MHz cavity amp with a GE 2500W dissipation monster tetrode. 
>>>>>> It was
>>>>>> designed for a KW out as an AM linear.
>>>>>>
>>>>>> Carl
>>>>>> KM1H
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> ----- Original Message -----
>>>>>> From: "Roger (K8RI)" <sub1 at rogerhalstead.com>
>>>>>> To: "jeremy-ca" <km1h at jeremy.mv.com>
>>>>>> Cc: "Amps" <amps at contesting.com>
>>>>>> Sent: Sunday, March 23, 2008 2:18 AM
>>>>>> Subject: Re: [Amps] What is this amp set up for
>>>>>>
>>>>>>
>>>>>> > jeremy-ca wrote:
>>>>>> >> When I first saw that listing it said modified; I see he has
>>>>>> revised >> it.
>>>>>> >>
>>>>>> >> Thats not a bad price for smoke on 222 if the tube is perfect and
>>>>>> >> trimming back the strip line should be rather easy
>>>>>> > I would think it's too high even with a new tube. Really nice ones
>>>>>> > unmodified on 2, or 6-meters have been going for around $1400
>>>>>> (give or
>>>>>> > take)  Look carefully at the top.  It is bent in and has a
>>>>>> circular row > of
>>>>>> > what appear to be holes.  I have one on 2 that is *almost*
>>>>>> mint.  It
>>>>>> > looked crappy when I purchased it at a swap.  I figured I could
>>>>>> use it > for
>>>>>> > parts and hoped for a reasonably good tube.  A little cleaner and
>>>>>> it > looks
>>>>>> > almost new with a good tube.
>>>>>> >
>>>>>> > 73
>>>>>> >
>>>>>> > Roger (K8RI)
>>>>>> >>
>>>>>> >> My own amp for 222 is a 8877 and I scaled down a 2M version and
>>>>>> then >> used
>>>>>> >> a VNA for final trimming. I built it in a partially built Henry
>>>>>> 44-46 >> MHz
>>>>>> >> box I picked up in a swap.
>>>>>> >>
>>>>>> >> Carl
>>>>>> >> KM1H
>>>>>> >>
>>>>>> >>
>>>>>> >> Carl
>>>>>> >> KM1H
>>>>>> >> ----- Original Message ----- From: "Roger (K8RI)"
>>>>>> >> <sub1 at rogerhalstead.com>
>>>>>> >> To: "jeremy-ca" <km1h at jeremy.mv.com>
>>>>>> >> Cc: "Amps" <amps at contesting.com>
>>>>>> >> Sent: Saturday, March 22, 2008 9:19 PM
>>>>>> >> Subject: Re: [Amps] What is this amp set up for
>>>>>> >>
>>>>>> >>
>>>>>> >>> jeremy-ca wrote:
>>>>>> >>>> Hmmm, his description says it is modified for 220.
>>>>>> >>>
>>>>>> >>> Isn't that "modifiable" to 220?
>>>>>> >>> Although advertised as a 2-meter amp, "I'd guess" it's one of
>>>>>> those >>> that
>>>>>> >>> was used for plasma or industrial heating at 200 MHz that can be
>>>>>> >>> modified for 220.  Some outfit has had a similar one in very
>>>>>> nice >>> shape
>>>>>> >>> (with new tube)on there since last Fall with no takers.  Their
>>>>>> BIN >>> price
>>>>>> >>> has finally started down.  Unless they find some one who really
>>>>>> wants
>>>>>> >>> (and can use) one for 220 both are basically parts amps.
>>>>>> >>>
>>>>>> >>> I purchased one all set up for the 2-meter band in good shape
>>>>>> that >>> only
>>>>>> >>> required a good cleaning for less than he's asking for one
>>>>>> that may
>>>>>> >>> require a lot of work.  I was learning about building filters
>>>>>> for it >>> on
>>>>>> >>> here last summer.
>>>>>> >>>
>>>>>> >>> 73
>>>>>> >>>
>>>>>> >>> Roger (K8RI)
>>>>>> >>>> Carl
>>>>>> >>>> KM1H
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>> ----- Original Message ----- From: "Roger (K8RI)"
>>>>>> >>>> <sub1 at rogerhalstead.com>
>>>>>> >>>> To: "Amps" <amps at contesting.com>
>>>>>> >>>> Sent: Saturday, March 22, 2008 7:59 PM
>>>>>> >>>> Subject: [Amps] What is this amp set up for
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>>> the amp listed on
>>>>>> >>>>>
>>>>>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350038955687&ssPageName=ADME:X:AAQ:US:1123
>>>>>> >>>>> is listed as a 2-meter amp but the specs list it as 200 MHz
>>>>>> +/-10 >>>>> Mhz.
>>>>>> >>>>> Also the output filter is far smaller than the one in my
>>>>>> 2002A >>>>> which
>>>>>> >>>>> is
>>>>>> >>>>> set up for 2-meters.
>>>>>> >>>>>
>>>>>> >>>>> 73
>>>>>> >>>>>
>>>>>> >>>>> Roger (K8RI)
>>>>>> >>>>> _______________________________________________
>>>>>> >>>>> Amps mailing list
>>>>>> >>>>> Amps at contesting.com
>>>>>> >>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>> >>>>>
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>
>>>>>> >>>
>>>>>> >>
>>>>>> >>
>>>>>> >
>>>>>> >
>>>>>>
>>>>>> _______________________________________________
>>>>>> Amps mailing list
>>>>>> Amps at contesting.com
>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
> 