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Re: [TenTec] OT: Scopes

 To: "'Discussion of Ten-Tec Equipment'" Re: [TenTec] OT: Scopes "Rick - DJ0IP / NJ0IP" Discussion of Ten-Tec Equipment Mon, 20 Feb 2012 20:15:39 +0100 mailto:tentec@contesting.com>
 ```Well you can look at it all day long (hi), but if you want to measure it... I guess my question is, what are you wanting to look at when you measure across the plate> Measure the amplitude with a voltmeter. Measure the signal on the other side of the capacitor. If you are looking for things like the ripple on the DC, then be sure your probe and voltmeter can handle the voltage. To be honest, if that's what you want to do, then look for a scope with 400 or 500 volt ratings, not 250. The safest way then would to build yourself a voltage divider with a pair of resistors, and measure in between the resistors. That way you can look at the ripple without having the full voltage on your probe. 73 Rick, DJ0IP -----Original Message----- From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com] On Behalf Of kc9cdt@aol.com Sent: Monday, February 20, 2012 7:48 PM To: tentec@contesting.com Subject: Re: [TenTec] OT: Scopes Rick, What if I want to look at the plate? Thanks, Lee -----Original Message----- From: Rick - DJ0IP / NJ0IP To: 'Discussion of Ten-Tec Equipment' Sent: Mon, Feb 20, 2012 1:30 pm Subject: Re: [TenTec] OT: Scopes Lee, The RF or Audio signal from the RX stage is passed on through a capacitor to the next stage, otherwise you would have the high voltage on the input of the next stage. Measure on the other side of the capacitor, not on the high voltage side. You need to consider the voltage specs of the probe, but most should be good for 250v. 73 Rick, DJ0IP -----Original Message----- From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com] On Behalf Of kc9cdt@aol.com Sent: Monday, February 20, 2012 7:00 PM To: tentec@contesting.com Subject: Re: [TenTec] OT: Scopes I guess the real question originated from me..to Dave.....I asked about 2500 volts as a 10x question not as if I want to measure that voltage...I know much better. I would use a HV prove on a VTVM. .it wasn't that we want to measure that high of voltage...just making sure I (we) understand the scopes max input so as not to damage it. If it says 250 P-P and I want to measure a waveform from the plate of a stage of a RX with plate voltage of 150 volts and I'm using a 10x probe, I should be fine?? The question was more of a 10x probe question...are they marked with the max voltage? Or do you have to look up the specs? What is typical? What is realistic in practise? Thanks, 73, Lee -----Original Message----- From: Rick - DJ0IP / NJ0IP To: 'Discussion of Ten-Tec Equipment' Sent: Mon, Feb 20, 2012 12:46 pm Subject: Re: [TenTec] OT: Scopes Dave, you can even measure 25,000 volts with it - ***ONCE IN YOUR LIFETIME***. Scopes are not foreseen for measuring high voltage. They are for measuring signals and wave shapes, etc. There are better instruments for measuring high voltage and in all cases you should be using a purpose-built high-voltage probe. 73 Rick, DJ0IP -----Original Message----- From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com] On Behalf Of Dave Edwards Sent: Monday, February 20, 2012 6:12 PM To: tentec@contesting.com Subject: Re: [TenTec] OT: Scopes Another list member and I were wondering......If a scope's front panel says max 250 volts P/P....does that mean if you have a X10 probe, you can then measure 2500 volts...(safely)? ....Dave On 2/20/2012 9:07 AM, kc9cdt@aol.com wrote: > Buy from a reputable dealer not at the hamfest IF you want more > assurance. > Actually when you get at least a working (check it out as much as you > can there) scope at a hamfest....being perectly calibrated in most > cases is not critical for our work. > That assumes you talking boat anchors, like I work on. > 73, > Lee > > > > -----Original Message----- > From: Richards > To: Discussion of Ten-Tec Equipment > Sent: Mon, Feb 20, 2012 12:00 am > Subject: Re: [TenTec] OT: Scopes > > > Please excuse me if I missed it... but I don't recall anyone explaining > to the unwashed... > > What can one do to avoid getting a lemon or broken > or poorly calibrated, or whatever broken, oscilloscope > at the local hamfest ? > > This item is beyond my current expertise, but it may not be > forever beyond my grasp. How do I avoid getting stung (other > than to buy something new?) What do I look for if I don't have > my favorite Elmer on hand ? > > Thanks. > > ---------------------------- K8JHR ---------------------------------- > > On 2/19/2012 2:06 PM, Jim Lowman wrote: > >> Interesting, Steve! Your memory is much better than mine, since I > _______________________________________________ > TenTec mailing list > TenTec@contesting.com > http://lists.contesting.com/mailman/listinfo/tentec > > _______________________________________________ > TenTec mailing list > TenTec@contesting.com > http://lists.contesting.com/mailman/listinfo/tentec > _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec ```
 Current Thread Re: [TenTec] Reputable dealer vs Hamfests, (continued) Re: [TenTec] Reputable dealer vs Hamfests, k3miy Re: [TenTec] Reputable dealer vs Hamfests, Rick - DJ0IP / NJ0IP Re: [TenTec] OT: Scopes, Dave Edwards Re: [TenTec] OT: Scopes, Phil Chambley, Sr. Re: [TenTec] OT: Scopes, Tim Re: [TenTec] OT: Scopes, Mike Bryce Re: [TenTec] OT: Scopes, Rick - DJ0IP / NJ0IP Re: [TenTec] OT: Scopes, kc9cdt Re: [TenTec] OT: Scopes, Rick - DJ0IP / NJ0IP Re: [TenTec] OT: Scopes, kc9cdt Re: [TenTec] OT: Scopes, Rick - DJ0IP / NJ0IP <= Re: [TenTec] OT: Scopes, kc9cdt Re: [TenTec] OT: Scopes, Ken Brown Re: [TenTec] OT: Scopes, Ken Brown Re: [TenTec] OT: Scopes, Ken Brown Re: [TenTec] OT: Scopes, kc9cdt Re: [TenTec] OT: Scopes, Ken Brown Re: [TenTec] OT: Scopes, Ken Brown Re: [TenTec] OT: Scopes, Phil Chambley, Sr. Re: [TenTec] OT: Scopes, Stuart Rohre Re: [TenTec] OT: Scopes, Ken Brown