[Amps] What is this amp set up for

jeremy-ca km1h at jeremy.mv.com
Sun Mar 23 08:52:46 EDT 2008


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
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
> 



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