UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Other Discussions > Homebrew Equipment

Notices

Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members.

Closed Thread
 
Thread Tools
Old 27th May 2009, 2:02 pm   #21
Skywave
Rest in Peace
 
Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
Arrow Re: Homebrew Q meter (or very nearly)

OK, Mike - I've now run out of suggestions on this. I'll now leave you to ponder, etc. Come back to us when you decide to move this further. It'll be interesting to see what eventually develops from this.

TTFN.

Al. / Skywave.
Skywave is offline  
Old 27th May 2009, 2:54 pm   #22
MichaelR
Retired Dormant Member
 
MichaelR's Avatar
 
Join Date: Mar 2006
Location: Sheffield, South Yorkshire, UK.
Posts: 1,587
Default Re: Homebrew Q meter (or very nearly)

Hi Al,

I will get back to you with my next move the interesting link is the middle one that jimmc passed through.The author has designed a purpose Q meter but interestingly he has the same thoughts about capacitor divider and HigZ buffering around the EUT, I think we are going in the right direction because that has been published as a design in the States. There are some good ideas about the construction of the test jig.

Thanks for your support

Mike
MichaelR is offline  
Old 27th May 2009, 4:17 pm   #23
Skywave
Rest in Peace
 
Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
Default Re: Homebrew Q meter (or very nearly)

Whoops! I've just had another after-thought!

I do recall that quite some time back, an article was published in Practical Wireless for a Q-meter; I may be able to dig my copy out (archived ).

I know that this is tangential to your approach; would it be of any interest to you?

Al.
Skywave is offline  
Old 27th May 2009, 6:39 pm   #24
MichaelR
Retired Dormant Member
 
MichaelR's Avatar
 
Join Date: Mar 2006
Location: Sheffield, South Yorkshire, UK.
Posts: 1,587
Default Re: Homebrew Q meter (or very nearly)

Hi Al,

All information is of use, just to prove the approach is not the one take can be just as valuable !!

Thanks again

Mike
MichaelR is offline  
Old 28th May 2009, 1:59 am   #25
fredtothefifth
Retired Dormant Member
 
Join Date: Sep 2008
Location: wakefield
Posts: 4
Default Re: Homebrew Q meter (or very nearly)

The series resonance method works well, especially out beyond 10MHz where (conventionally) maintaining a high shunt Z becomes a real problem. The kit simply consists of a good quality tuning capacitor, thereby moving the measuring complications onto the spectrum analyser etc.
Only drawback is that the Q is now measured w.r.t. 50ohms and needs some sums doing!.
Attached Thumbnails
Click image for larger version

Name:	Q-jig1.jpg
Views:	113
Size:	88.9 KB
ID:	25850  
fredtothefifth is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 3:27 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.