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Re: [Amps] What is this amp set up for

To: jeremy-ca <km1h@jeremy.mv.com>
Subject: Re: [Amps] What is this amp set up for
From: "Roger (K8RI)" <sub1@rogerhalstead.com>
Date: Sun, 23 Mar 2008 10:34:04 -0400
List-post: <amps@contesting.com">mailto:amps@contesting.com>
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.
If you'd move to Michigan you'd not have a problem with expensive 432 
amps.  They are downright cheap over here. Of course we can only run 50 
watts so that might factor in there somewhere. <:-))
OTOH I'm looking at eventually building something for 2.4 and 5 Gig.

73

Roger (K8RI)
> 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@rogerhalstead.com>
> To: "jeremy-ca" <km1h@jeremy.mv.com>
> Cc: "Amps" <amps@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@rogerhalstead.com>
>>> To: "jeremy-ca" <km1h@jeremy.mv.com>
>>> Cc: "Amps" <amps@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@rogerhalstead.com>
>>>>> To: "Amps" <amps@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@contesting.com
>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
>

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