[TenTec] Orion II - Tech Topics

[Martin AA6E]

There are two technical issues here.  Stability is not the same thing as 
accuracy.

While you can track a definite warm-up drift of about 1 ppm over some 
hours, the stability of the Orion's TCXO is fine for most any ham 
operation.  See 
http://blog.aa6e.net/2005/08/orion-frequency-calibration.html .

Accuracy is a different matter.  The actual setting of your TCXO can be 
several ppm off, depending on the factory's precision, your ambient 
temperature, crystal aging, etc.  This means that when you dial in your 
favorite net frequency, you could be more than 20 Hz off at 14 Mhz, and 
worse at higher freqs.  That is enough to notice on SSB for a trained 
ear.  (Many rigs on the air are a lot worse, of course. Either that, or 
a lot of ears are not well trained. Or both!)

If you are interested in accurate frequency measurement, it is possible 
to use the Orion for sub-ppm measurements by careful calibration against 
a standard like WWV.  See 
http://blog.aa6e.net/2006/01/2005-freq-measurement-test-results.html .

The Orion "dial" can be set to 1 Hz at 30 MHz.  If that were fully 
accurate, it would be better than .03 ppm.  So there is room for 
improvement! 

How much is that worth in terms of selling price?  Not a lot for most of 
us, but the good news is that a better oscillator need not be 
expensive.  Icom's IC-7000 claims 0.5 ppm (6 times better) for a cheaper 
rig than Orion.  An after-market add-on would cost more, of course.  I 
suppose I'd pay $50-100 without complaint, but not $300.  No reason this 
has to come from TT.  It could be a good deal for a 3rd party entrepreneur.

A caution: make sure the phase noise is no worse than the current TCXO.  
Many voltage-trimmable oscillators have worse phase noise specs.

73 Martin AA6E

James Duffer wrote:
> snip
>
> Sorry but from my point of view it isn't worth that much additional cost for 
> that improvement.  The stability of my Omni VI, and FT-1000D is more than 
> satisfactory for my use.  Maybe an option where those who think they require 
> that additional stability??
>
> Looking at the radios that I have owned in the past, SB-300, KWM-2, Swan 350 
> (!), HW-16, TenTec 544 etc.  Frequency stability has improved with the newer 
> radios and I have no problems with the current frequency stability.
>
> Jim wd4air
>
>   
>> If we want real frequency stability, here is what is needed:
>>
>> http://www.bliley.com/n47x___nv47x___co_08.pdf
>>
>> I wonder if TT would be willing to order a few of these custom since a
>> volume purchase would be needed, and offer them as an option on new units
>> and a mod to existing units?  It would require a simple board to solder to
>> the existing circuit board, but there is plenty of room to accommodate it.
>> They could also add a trim pot on the board to fine calibrate if the 'EFC'
>> version is used.  Imagine having frequency stability and accuracy to one
>> part per 10 million and 10 dB better phase noise, too!
>>
>> I'd pay $200-$300 for that, which would build in a fair profit for TT if
>> more than a couple dozen were sold.
>>
>> Ron N6AHA
>>
>>     
> snip
>
>
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