need RF equipment recommendation

Not a used equipment vendor, but using highly-available parts...

Tom McEwan's patents have schematics for his various radars, including the SRD-based ones which have rise times like that. He even lists preferred vendors for some parts. I'm looking forward to having time to play in that space myself.

That was interesting reading. Thanks.

ChesterW

Wait a minute ... for a project like this you're going to need people that know how to do it. Those people will know what equipment they need. It just seems screwy that somebody wants to do a project and doesn't know what equipment will be needed.

Bob

Ebay Tektronics 11801 scope and a sampling head. The SD22 head is good, low noise and 14 GHz. But the SD24 head does TDR, which means it basically has a built-in 30 ps pulse generator. I've seen a signal from one SD24 channel into the other, through a pair of wideband antennas.

There is a probe head for the 11801, the SD14, 3 GHz at the tip.

If you're working wideband, you could stay in time domain and avoid the VNA.

That gear is relatively cheap, a few per cent of what new stuff would cost.

The 11801 is overkill for 200 ps, but a good deal anyhow.

--

John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

200 ps isn't hard--you can do that on a dead-bug proto.

Starting with an 11801-series scope is a good idea--you can get one for

1-2k at the moment. I'd want to spend another $3k for a TDS 694C, if possible, because sampling scopes like the 1180x are a bit frustrating if you don't know when exactly your signal is going to arrive.

For the OP: The reason is that all the input circuitry of a sampling scope is hidden behind the sampling bridge, so whatever happens between samples is invisible to it. That means that you can't trigger a sampling scope from its signal inputs, the way you do with an ordinary scope.

Jim Williams points out that that makes samplers just the ticket for measuring the settling transients of fast amplifiers. They're also good for an amazing number of other things, if you can get the trigger pulse from somewhere.

The TDS 694C has about 125 ps rise time, 10 Gs/s simultaneously on all four channels. It's an amazing amount of bang for the buck.

(Can you tell that I'm still in love?) ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Oh, one other suggestion: an HP 70820A Microwave Transition Analyzer, about $800. I have no idea what moron gave it its name, but the gizmo itself is astounding. It's a sampler-based, 40-GHz vector network analyzer / spectrum analyzer / dual channel oscilloscope.

It's a wonderful piece of gear for the sort of job under discussion, and very very cheap because nobody knows what it does!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Thanks! You guys are the greatest.

ChesterW

--

Best Regards, 

ChesterW 
+++ 
Dr Chester Wildey 
Founder MRRA Inc. 
Electronic and Optoelectronic Instruments 
MRI Motion, fNIRS Brain Scanners, Counterfeit and Covert Marker Detection 
Fort Worth, Texas, USA 
www.mrrainc.com 
wildey at mrrainc dot com

If somebody ever figures out how to market the 70820A, let me know, because I've always wanted to build one. :-P

-- john, KE5FX

Yes, we are. Don't forget you can also *hire* network analyzers which might be a better idea than lashing out BIG DOUGH on an outright purchase. Last time I looked there was some guy on Ebay hiring VNAs and a all sorts of other high-end test equipment from the best manufacturers: Agilent, LeCroy n' shit. :)