On 12/27/2016 6:19 PM, nuny@bid.nes wrote:> On Monday, December 26, 2016 at 9:41:34 AM UTC-8, mixed nuts wrote: >> On 12/26/2016 11:58 AM, Steve Wilson wrote: >>> BioPhysics2016 <mabdelaleem2012@gmail.com> wrote: >>> >>>> Hello, >>>> >>>> I'm building Nuclear Quadrupole Resonance (NQR)to test for 14N. using >>>> the SpinCore Radio processor USB board. Here is the manual of the >>>> board. >>>> http://www.spincore.com/CD/RadioProcessor/RadioProcessor_manual.pdf >>>> >>>> I could not find low-cost 50/100/200 Watts RF power amplifiers(0.25 - >>>> 10 MHz). >>>> >>>> I have just found the following RF power amplifiers: >>>> >>>> 1- ENI 325LA RF Power Amplifier, 250 kHz to 150 MHz, 25 W, 50 dB >>>> >>>> http://www.bellnw.com/manufacturer/ENI/325LA.htm?gclid=Cj0KEQiAnIPDBRC7 >>>> t5zJs4uQu5UBEiQA7u5NexeWcgCpwmo8gfkBHI8TfT7SR8hTVzjdJTujqguMjC8aAkaK8P8 >>>> HAQ >>>> >>>> 2- KAA4020 500 Watts CW, 1 - 50 MHz >>>> >>>> http://www.arww-modularrf.com/post/KAA4020%20(7-98-836-003A).pdf >>>> >>>> I just want to know, Is it possible to use the continuous wave (CW) >>>> amplifiers to amplify the pulsed singals generated by the >>>> RadioProcessor board? >>>> >>>> Or I have to use the pulsed amplifiers only? >>>> >>>> A waiting your reply as soon as possible >>>> >>>> Thanks >>> >>> Why not get an RF amplifier made by SpinCore. They have two models: >>> >>> http://www.spincore.com/CD/RFPA/RFPA_Manual.pdf >>> >>> Any reason for wanting do do NMR? Apparently it is not very sensitive and >>> requires a strong magnet: >>> >>> https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance >> >> NQR is not NMR. No magnet required. >> >> https://en.wikipedia.org/wiki/Nuclear_quadrupole_resonance > > There's also low-field and zero-field NMR for half-integer-spin isotopes: > > https://en.wikipedia.org/wiki/Low_field_nuclear_magnetic_resonance > > https://en.wikipedia.org/wiki/Zero_field_NMR > > For integer-spin isotopes like N14 NQR is the ticket.Yep. Cut my teeth in the late 60s on a Varian HA-60. Almost 45 years of NMR under my belt as "not a chemist" working for one or another of the major manufacturers. Still doing it. Had a gap for a few years in aerospace electronics and instrumentation but home has always been snuggled up to a big magnet. -- Grizzly H.
RF power amplifier for Nuclear Quadrupole Resonance (NQR) spectrometer
Started by ●December 26, 2016
Reply by ●December 30, 20162016-12-30
Reply by ●January 4, 20172017-01-04
On Thursday, 29 December 2016 16:52:11 UTC-8, Bill Beaty wrote:> On Monday, December 26, 2016 at 5:23:16 AM UTC-8, BioPhysics2016 wrote: > > > I could not find low-cost 50/100/200 Watts RF power amplifiers(0.25 - 10 MHz). > > Here in UW chem, our older NMR power amps are either ENI wideband amp (like ENI 350 or 3100,) or amateur radio "linear" broadband amps from Henry Radio. > > On ebay I see several used ENI amps for $1,500 and up. In the past I've seen these for under $200, but non-working with dead output transistors (so, buy and repair!) > > > I just want to know, Is it possible to use the continuous wave (CW) amplifiers to amplify the pulsed singals generated by the RadioProcessor board? > > Yes. > > It appears that the main difference with "pulse" amplifiers is the added probe-protecting features, which shut down the output whenever detecting long pulses, CW, or PWM above ~20%. > > An amateur radio CW amplifier under $1000 should work fine. (Some of those ham amp kits are under $100!) But it lacks the automatic protection. Just make sure to avoid accidental oscillation caused by old corroded BNC cables with bad shielding. That, or undergrad students who burn up your match networks with wrong software settings. > > Also check out: > > https://www.jiscmail.ac.uk/cgi-bin/webadmin?A0=CCPNMR > > http://qa.nmrwiki.org/ > > http://www.bionmr.com/forum/nmr-questions-answers-24/Thank you Bill very much for your reply. Could you please check this power amplifier from RM Italy http://www.ab4oj.com/amps/hla305v_notes.pdf Do you think it is OK to use this one. Thanks
Reply by ●January 4, 20172017-01-04
On Wednesday, January 4, 2017 at 7:39:13 PM UTC+11, BioPhysics wrote:> On Thursday, 29 December 2016 16:52:11 UTC-8, Bill Beaty wrote: > > On Monday, December 26, 2016 at 5:23:16 AM UTC-8, BioPhysics2016 wrote: > > > > > I could not find low-cost 50/100/200 Watts RF power amplifiers(0.25 - 10 MHz). > > > > Here in UW chem, our older NMR power amps are either ENI wideband amp (like ENI 350 or 3100,) or amateur radio "linear" broadband amps from Henry Radio. > > > > On ebay I see several used ENI amps for $1,500 and up. In the past I've seen these for under $200, but non-working with dead output transistors (so, buy and repair!) > > > > > I just want to know, Is it possible to use the continuous wave (CW) amplifiers to amplify the pulsed singals generated by the RadioProcessor board? > > > > Yes. > > > > It appears that the main difference with "pulse" amplifiers is the added probe-protecting features, which shut down the output whenever detecting long pulses, CW, or PWM above ~20%. > > > > An amateur radio CW amplifier under $1000 should work fine. (Some of those ham amp kits are under $100!) But it lacks the automatic protection. Just make sure to avoid accidental oscillation caused by old corroded BNC cables with bad shielding. That, or undergrad students who burn up your match networks with wrong software settings. > > > > Also check out: > > > > https://www.jiscmail.ac.uk/cgi-bin/webadmin?A0=CCPNMR > > > > http://qa.nmrwiki.org/ > > > > http://www.bionmr.com/forum/nmr-questions-answers-24/ > > Thank you Bill very much for your reply. > > Could you please check this power amplifier from RM Italy > > http://www.ab4oj.com/amps/hla305v_notes.pdf > > Do you think it is OK to use this one.I can't see any reason why it wouldn't be. The tests described don't include any short pulse tests, and it could be that inter-stage coupling might not respond well to short bursts - you might need to ensure that each pulse sequence had a zero DC content or something equally difficult to guarantee. What would be more useful would be the circuit diagram - and there are people here who would do a better job on that than I would. The e-mail address I use here is real, and does work. The IEEE spam filtering works remarkably well. -- Bill Sloman, Sydney
Reply by ●January 4, 20172017-01-04
On Wednesday, January 4, 2017 at 8:10:49 AM UTC-5, bill....@ieee.org wrote:> On Wednesday, January 4, 2017 at 7:39:13 PM UTC+11, BioPhysics wrote: > > On Thursday, 29 December 2016 16:52:11 UTC-8, Bill Beaty wrote: > > > On Monday, December 26, 2016 at 5:23:16 AM UTC-8, BioPhysics2016 wrote: > > > > > > > I could not find low-cost 50/100/200 Watts RF power amplifiers(0.25 - 10 MHz). > > > > > > Here in UW chem, our older NMR power amps are either ENI wideband amp (like ENI 350 or 3100,) or amateur radio "linear" broadband amps from Henry Radio. > > > > > > On ebay I see several used ENI amps for $1,500 and up. In the past I've seen these for under $200, but non-working with dead output transistors (so, buy and repair!) > > > > > > > I just want to know, Is it possible to use the continuous wave (CW) amplifiers to amplify the pulsed singals generated by the RadioProcessor board? > > > > > > Yes. > > > > > > It appears that the main difference with "pulse" amplifiers is the added probe-protecting features, which shut down the output whenever detecting long pulses, CW, or PWM above ~20%. > > > > > > An amateur radio CW amplifier under $1000 should work fine. (Some of those ham amp kits are under $100!) But it lacks the automatic protection. Just make sure to avoid accidental oscillation caused by old corroded BNC cables with bad shielding. That, or undergrad students who burn up your match networks with wrong software settings. > > > > > > Also check out: > > > > > > https://www.jiscmail.ac.uk/cgi-bin/webadmin?A0=CCPNMR > > > > > > http://qa.nmrwiki.org/ > > > > > > http://www.bionmr.com/forum/nmr-questions-answers-24/ > > > > Thank you Bill very much for your reply. > > > > Could you please check this power amplifier from RM Italy > > > > http://www.ab4oj.com/amps/hla305v_notes.pdf > > > > Do you think it is OK to use this one. > > I can't see any reason why it wouldn't be. The tests described don't include any short pulse tests, and it could be that inter-stage coupling might not respond well to short bursts - you might need to ensure that each pulse sequence had a zero DC content or something equally difficult to guarantee.Yup, the one issue I had years ago with a RF amp I built was some inter-stage coupling that would ring down when the RF was turned off. That lead to a little bit of "weirdness" when trying to get perfect 180 degree pulses. (For NMR) George H.> > What would be more useful would be the circuit diagram - and there are people here who would do a better job on that than I would. > > The e-mail address I use here is real, and does work. The IEEE spam filtering works remarkably well. > > -- > Bill Sloman, Sydney
