Thank you. I appreciated your humor.
But for serious measure, I will look for a serious device. Of course.
Out of curiosity, what's the unit of measurement of "Device Seriousness"? Would 10 MegaSeriousnets do? 
I wouldn't wait with bated breath for any reply to this question, despite the unfulfilled promise of "getting back with an answer tomorrow" (it's been a month without any further appearance in this thread since he made that promise). Whilst he's been a member for just over three years, he's only posted 13 times with the last 6 of them being here in the space of an hour blowing a whole 546 day's worth of activity in the process, almost doubling his activity rate to 0.011 posts per day!
I suspect the contrast in price between a "Toy" that would still more than suffice to answer the question "Did that BW licence upgrade actually have any effect or not?" and a professional grade RF Signal Generator capable of permitting flatness curve measurements to +/-0.1dB or better costing tens of thousands of dollars must have prompted a "Shoot from the hip" posting which he's now probably regretting (I do know that feeling all too well
).
I've been reading this thread for almost a fortnight since viewing Dave's and The Defpom's review / teardown videos and this unchallenged assertion that this toy 35 to 4000MHz VFO module would be of no use whatsoever as a cheap means of verifying whether or not a BW upgrade has actually taken effect, has been irritating me over the past week since reading famalex's posts. Personally, I'd expect with 500MHz being only 12.5% of a 4GHz BW, it would more than suffice for making such sanity checks on the new BW limits of a hacked 'scope.
I rather think that, since nobody else has mentioned the merits (or not) of a "cheap toy" VFO module, rather than return to apologise for his hasty dismissal of this "toy", he's decided to keep his head below the parapet and keep shtum - let sleeping dogs lie and all that. TBH I think, given the seeming lack of interest, I'd do the same.
I've been pondering the need to upgrade my SDS1202X-E "Toy" (it had only cost a mere £365 just 18 months ago
) over the past 3 or 4 weeks ever since I started running comparative phase stability tests between my mark I and mark II basic GPSDO designs using my "Toy" FY6600-60M function generator (a mere bauble at just £76 plus a few bits 'n' bobs for upgrade components, circa another 60 quid tops) to externally trigger it with a 10MHz Sinc pulse which, trimming for temperature changes once every few hours using the 2GT effect to fine tune the ppt variations (mostly diurnal temperature variations with an all but invisible ageing component) that still manage to afflict the 10MHz ovenised crystal oscillator reference (with 3n502 clock multiplier chip) that has replaced the original 20ppm rated 50MHz smd XO.
I'm looking at the ionospheric effects on the phase of the 10MHz disciplined OCXO in each GPSDO. Both are basic hardware PLL designs with M8N gps receiver modules, the first using a TC of 500, the second, using a more ambitious TC of 5000 in order to tame these sub subsonic phase modulations.
In order to get some idea of the level of these phase shifts, I needed an independent, free running reference that's at least stable enough in frequency from hour to hour for these phase shifts to be revealed for what they really are, sub subsonic phase modulation noise created by imperfect GPS correction data for changes in the ionosphere's electron density. My
upgraded toy FG fulfils this need quite nicely (Yey! Yet another win for "Toy" T&M kit
).
Commodity priced navigation only GPS receiver modules aren't the best choice for such basic hardware PLL driven designs. If you want to avoid using a microcontroller to function as a long time constant DSP PLL using a Kalman filtering algorithm to filter out the sub subsonic (mHz to uHz range) phase modulation noise, a timing module is the only alternative way to achieve such low sub subsonic phase noise performance with a traditional hardware PLL setup.
I finally located and ordered a cheapish (41 quid delivered) M8T module a few days ago - the trouble is it's from a Chinese reseller on Amazon and estimated delivery is the beginning of August
. Hopefully, I'll have taken delivery of an SDS2104X+ a week or two earlier.
Being able to actually
observe the triggering waveform on a third channel (along with all the tunable triggering options this brings, plus a 20 fold reduction in triggering jitter) is just one of the many improvements I'm looking to obtain by splashing out some £1260 on an SDS2104X+ (I'm currently negotiating a 5% discount off the UK price with my DSO supplier, Labtronix - with luck, I might hear some good news on that front by Monday).
I've only seen one other UK supplier (but, afaicr they're not an official Siglent distributor - I could be wrong). I'll have another look for other UK based T&M kit resellers who might be prepared to offer an EEVBlog (or any) discount whilst I await Labtronix's answer.
If any other UK based EEVBlog members have any UK supplier recommendations to offer, now would be the ideal time to step forward with all your money saving recommendation(s).
JBG
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