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Old 13th Apr 2021, 10:35 pm   #22
ortek_service
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Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,398
Default Re: Which signal generator?

Yes I once had the pair of those Marconi Sign Gen + the Synchroniser unit, I had been given. But I donated to someone else, as already had / already too used to using some a bit more modern fully digital-entry/display synthesised ones I'd managed to get cheap from work sales.

And you may now be able to pickup Marconi 2018/2019 or even 2022 ones for a reasonable price, that are all fully-synthesised but quite old.
The classic 203x/204x models superseded these and were amongst the best, bust still probably a bit pricey - > £500 for a working one, although you may get one that needs fixing for less as many were scrapped when attenuators etc. played up due to silly repair prices (but DIY cleaning may often fix)
Marconi Instruments became IFR, Aeroflex then finally part of Cobham, who sadly closed all of this division down a few years ago so little support even for later models although there is a very active repair group with some ex-employees: https://groups.io/g/Marconi-Test-Instruments/

When fully-working, these will generally give you known very good performance.
In terms of much-newer models, the usual fairly-budget instrument makers like TTI, Rigol, Siglent etc. seem to now only do fairly high frequency RF signal generators, so quite a bit over £1k new. For a bit lower frequencies, they do some much more reasonably-priced Arbitrary / Function generators but these won't have the minimum output level / shielding required for this.
Digimess have a rather basic SG100 150MHz RF Sig Gen in Farnell etc. but it doesn't look like you could set frequency very accurate or output level very low. Their SG200 DDS looks much better but nearly £1k new, and probably difficult to get a cheap used one.

You can get MC1648 lots of cheap pre-built narrow range signal source module, that may overcome the potential issues with that Nuts&Volts project that doesn't even use proper PCB's.

Another option maybe Analog devices ADFxxxx PLL evaluation boards, but their minimum frequency can often be quite high.
Alternative there's quite a lot of Software Defined Radio units, that can also generate RF signals over a wide range.

These will mostly require a PC to control them, but can be made to do virtually anything regarding frequency / modulation that way - as well as many also being a receiver with spectrum display etc. e.g. The HackOneRF that isn't too bad new, but seem suspiciously cheap on:
https://www.banggood.com/Wholesale-S...r-c-11802.html

There is also a similar thing, that is fully-integrated with a controller:
https://coolcomponents.co.uk/product...enerator-combo
Unfortunately, the half priced version only starts at 24MHz:https://coolcomponents.co.uk/product...efff721c&_ss=r

And an RF output attenuator will be required to get much lower levels.
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