[QuadList] Merlin vs stock Ampex

[C. Park Seward]

So the burst with a little more high-end response is the Merlin. Even though both have the same low pass filter.

DSC01343.JPG

With the T pulse, the one with the less ripple is the Merlin, the top photo.

I don't think these measurements would affect the picture very much with perhaps the Merlin looking a little sharper and the stock Ampex looking a little more "analog".

Best,
Park

C. Park Seward
Cell: 818-535-2747
Home: 949-679-1870
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On Dec 22, 2009, at 4:52 PM, C. Park Seward wrote:

> Hi Don,
> 
> I was looking to compare just the electronic section so the pictures were made in EE so as not to influence the result with tape and head issues.
> 
> Both machines have the "good" 4.5 MHz filter.
> 
> I don't know the frequencies of the packets but here is a sweep. It has no burst.
> 
> 
> Best,
> Park
> 
> C. Park Seward
> Visit us: http://www.videopark.com
> <DSC01343.jpg>
> DSC01343.JPG
> <DSC01325.jpg>
> DSC01325.JPG
> 
> 
> 
> 
> 
> On Dec 22, 2009, at 4:21 PM, Don Norwood wrote:
> 
>> Hi Park:
>> 
>> More questions than answers....  What are the frequencies of the mutiburst packets?  Also, how are the measurements made (EE or playback)?  For some reason, 1328 has no color burst, so I'm not sure if the waveform is "valid" to compare to 1340.
>> 
>> The performance of the 1200 is related to which filter is installed in the signal system.  The best is 4.5 MHz, and the response should be virtually flat to that point.  Based on that, I'm guessing that this is not a "standard" multiburst with the top packet at 4.2 MHz.  But if the packets are higher frequencies, how are the higher frequencies getting past the filter?  A more revealing test is to use a 5 MHz sweep instead of multiburst.  In any event, for comparison, both machines need to have the same filters.
>> 
>> Then you get into what part of the system is doing what.  It's good to look at the output of the demods to be sure that they are both correct and identical, and then compare it to the output of the machine.  That way you establish whether differences are in the signal system or in the processing.
>> 
>> Don
>> 
>> ----- Original Message ----- From: "C. Park Seward"
>> Subject: [QuadList] Merlin vs stock Ampex
>> 
>> 
>>> Here are some pics I took of the two machines. Same test signals, same scope.
>>> 
>>> Can you guess which one is which?
>>> 
>>> 
>> 
>> 
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