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发表于 2019-9-2 13:03:24
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作为Mutec Ref10的用户,为这贴加一把火。
看到楼主的测试后,我发了一份邮件给Mutec,把测试结果告知他们(包括本网页的LINK),并问询他们对此是否有相关解释。
首先为了免除误会,要说明下,我并不认为官方给出的任何说法就是正确的,我个人楼主一样,只相信事实数据测量。
无论官方说了什么,也不代表烧友们就可以作为凭证了。
事实上,我个人觉得MUTEC的官方数据确实显得极佳,有些虚标我也不会很惊讶。
但针对任何事情的观点与辩论就是这样,
至少双方都有发言的权利,
所以我贴一下MUTEC官方回复的邮件内容供大家参考,在此不翻译了, 有英语好的朋友代翻一下吧。
Dear Zhou Quan!
(I am sorry I don’t know which one is your first name?)
Thank you for your email and the link to the forum discussion. Something like that is at any time very interesting for us, of course, even if the content is problematic, like here. My first question is, are you the customer of the REF 10 which was measured here? Or is that the REF 10 of the guy who opened the thread in the forum?
I am sorry, but I am not able to read in Chinese language, thus I needed to use Google Translate to read the statements and I think that the translation is not the best one. I hope that I got the content correctly.
First off, the pictures shown in the thread of the different OCXOs were published by the author months ago to try to denunciate us and to present us as liar. Fact is, that the picture showing the larger OCXO shows a pre-production model. The smaller OCXO is the one we are selling. Anyway, both OCXOs are of same quality and manufactured in Germany, there are no differences. Thus, all speculations in regards of cost savings which lead to worse clock performance are lie!
As far as I understand the author has measured only the Grimm clock and the REF 10, all other plots shown are of other manufacturers or taken out of the web. The question is why did he not try to get the other clock products as well for his own (!) measurements? Why he is trusting the other manufacturer’s measurements, but our measurement is denunciated as lie? Why he is thinking that his way to measure is the only one right and not this one of a renowned manufacturer? At no point he is doubting at his measurements, but ours are the only wrong ones?
Secondly, when measuring a product like the REF 10 with a system like the presented Symmetricom 5115A, which is a bit dated because six years ago already the manufacturer was acquired by Microsemi, you definitely need a clock reference. That means a clock reference which is much better as the clock to be measured. That is ESSENTIAL because the 5115A has got no internal clock reference, as far as I know. Furthermore, the internal architecture of the 5115A is quite noisy, we would say too noisy to measure the REF 10 correctly, no matter how good the externally connected clock reference is. With a good clock reference you just about can measure the phase noise at 1 Hz, but already at 10 Hz the hardware noise floor is reached with the measurement system in use.
Nevertheless my question again, which clock reference was used – can you provide this answer? We could nothing find about that in the thread. The Symmetricom can only measure as good as the supplied clock reference is. I am sorry to say that, but it seems to us that here a clock reference was used which is of lower clock performance as the REF 10.
For your information, our oscillator manufacturer is measuring oscillators with various Noise XT systems, the REF 10 developer is measuring with a large Holzworth system and others as well. These are the most professional phase noise measurement systems, you are free compare those against the Symmetricom, if you would like.
All in all, the content of this discussion is very confusing in most parts and we think that many participants do not agree with the author. He also mired himself in contradiction what is not really trustful. But as said above, I am not sure whether the translator did a good job, or not. It may be that we can’t follow this discussion 100%ly. Thus, I will stop at this point with further impressions we have about that all.
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