[TenTec] OMNI VI Transmit IMD

[al_lorona@agilent.com]

Right, Paul. This is another way of approaching the question I posted last
week (about which no one has really had anything to say). If the same final
amplifier design can vary by that much... it throws into doubt the whole
concept of testing one unit and calling it representative of the whole lot.
Manufacturers need to be more clear about whether their specs are only
typical numbers -- that your radio may or may not achieve--  or guaranteed.
I suspect that they are only typical values and can vary quite a bit due to
the manufacturing process.

If that is true, then the measurements in QST's Product Review are much less
meaningful than we thought. There can be just too much variation between
units to attach any statistical significance to pulling one unit off of the
production line and testing it and then declaring that all other units act
like that one 'golden' unit. Note that this is not a statement about ARRL's
testing methods, but about the units they are testing.

In the business world, customers can get pretty upset if their unit does not
meet a certain spec. But that's because it's understood that the spec sheet
holds guaranteed numbers. In other words, if your unit doesn't meet these
specs, you get another one or get your money back. Correct me if I'm wrong,
but it's been my understanding that of Kenwood, Icom, Yaesu, and Ten Tec,
only Ten Tec has this kind of policy. But I don't know if Ten Tec's specs
are actually guaranteed.

I am writing this at the risk of chasing away even more subscribers to this
list. Another one unsubscribed just today. At this rate, by mid-November
there will be only two of us left.

Al  W6LX

> 
> 
> > It's peculiar that what must be essentially the same final 
> comes in with
> > much worse numbers when tested as the OMNI VI +.
> 
> That is why I take the tested and published IMD figures with 
> a grain of salt ...
> Performance as measured on one radio sample cannot be 
> extrapolated into the entire life cycle of the product.
> 
> -Paul, W9AC