[hpsdr] Gibratlar VCTCXO

[Grant Hodgson]

Rakon are developing a VCTCXO with a temperature stability of 0.14ppm 
over the range -20 - +70C.  Part number is IVT5300D (the 'V' means it is 
a VCTCXO, i.e. it can be pulled with an external voltage).

I've received some very early samples for evaluation for the uWSDR 
project; the phase noise spec. looks better than other TCXOs and the 
temperature stability is better than some OCXOs.  Price is expected to 
be about GBP22 for 100 off quantities, falling to GBP11 (eleven pounds) 
for 1000 off.  At the moment GBP1 = USD2.  That's far less than any new 
OCXO.

Data is here :- 
http://www.rakon.com/models/browse-model?model_id=262&model_type=O

I had to wait 5 months for the samples, I was one of, if not the, first 
to receive them, and I'm not sure if they are in full production yet; 
the data is still shown as preliminary.   However, I think this part 
would be a good contender for use on Gibraltar.

In the past, if you wanted a GPS-locked reference then you had to use an 
OCXO because there was a lot of jitter on the PPS signal from the GPS 
receiver - 1uS or more.  This needed averaging over a long period, 
sometimes over an hour, and the crystal oscillator had to be stable 
during that time, so an OCXO was needed.  Modern GPS receivers designed 
specifically for timing have jitters in the 10s of nS, and so the 
averaging period can be much less and a lower-spec. crystal oscillator 
such as a good TCXO can be used with similar results at a fraction of 
the cost and with a quicker lock time.

OK, it's a bit more complicated than that in practise but that's the 
essence of it.

regards

Grant  G8UBN
>
> Hi folks,
> this is what I have ordered as a first step into Gibraltar:
> 
> http://www.hcelectronics.cz/en/preoscil.php
> 
> then look for OCXO 3416 type.
> 
> They offer an improved version with low phase noise for
> EUR 160 per piece in single quantities incl. VAT and shipping. The 
> 'normal' version is 20 EUR less.
> 
> It will be delivered in 2nd week of July including measuring protocol.
> I think this is a good start.
> 
> For bigger quantities they offer a good discount.
> 
> 73
> Horst
> DL6KBF
>