1N34A-Diode,RF probe
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Hi,
I´d like to build the Rf probe from th K2 kit.Elecraft says I need a 1N34A Diode, but this one is hard to get in my small town.Can I take another one and which diode should I take? 73,Chris-OE5CSP |
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Chris,
The 1N34 is specified because it is a germanium type and the low voltage drop of the germanium junction is preferred for accurate readings at low RF Voltage levels. Other germanium diodes will do that task just as well. Watch the peak reverse voltage rating for the diode you choose, because that will limit the maximum RF voltage that you can measure without zapping the diode. A silicon diode can also be used for an RF Probe, but its accuracy at low RF Voltage measurements will not be as good because of the higher diode forward voltage. We are talking about the difference between 0.3 volts and 0.7 volts between a germanium diode and a 'run of the mill' silicon junction diode. The Schottky diodes are silicon and have a low forward voltage drop and should work fine in RF Probe applications. 73, Don W3FPR OE5CSP-Chris wrote: > Hi, > > I´d like to build the Rf probe from th K2 kit.Elecraft says I need a 1N34A > Diode, but this one is hard to get in my small town.Can I take another one > and which diode should I take? > > 73,Chris-OE5CSP > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by OE5CSP-Chris
Chris -
I think the 1N5711 is a suitable substitute. It is not a germanium diode, but rather a Schottky barrier silicon diode - sometimes called a "hot carrier" diode. Schottky type diodes have low forward drop and work well for most RF detector applications, and are readily available and inexpensive. - Jim, KL7CC OE5CSP-Chris wrote: > Hi, > > I´d like to build the Rf probe from th K2 kit.Elecraft says I need a 1N34A > Diode, but this one is hard to get in my small town.Can I take another one > and which diode should I take? > > 73,Chris-OE5CSP > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: 1N34A-Diode,RF probe
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In reply to this post by OE5CSP-Chris
In Europe you could use a OA-02 which is a germanium
diode. Jean-Claude PJ2BVU _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Don Wilhelm-4
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RE: 1N34A-Diode,RF probe
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In reply to this post by OE5CSP-Chris
Sorry for the typo: OA-92
PJ2BVU _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by AC7AC
It's common to recommend a Schottky as a replacement for the 1N34A.
I've done it myself. That's why I was surprised to find this web page - http://www.cliftonlaboratories.com/diode_vf_vs_if.htm where this guy discovers that the Schottky diode (1N5711, to be specific) can show some pretty high forward voltage drops. Turns out that the low drop we're all familiar with exists at quite low values of forward current -- less than 1 mA. At ~2 mA is a sort of breakpoint where Vf begins to increase at a faster rate than in the silicon or the germanium diodes. By ~10 mA, the 1N5711 has the highest forward voltage of all three. Quite an eye-opener! You might think that for the RF probe application, forward current will be small. Maybe it is. But often times small average currents are misleading if there's a short conduction angle (time). 72--Nick, WA5BDU --back to counting screws _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Nick:
In the standard RF probe configuration, the diode carries little to no current, as it works into a high impedance digital voltmeter, or, in the old days, a 50 uA moving coil meter. My Vf/If diode measurements are for currents quite a bit higher than involved in a typical RF probe. If I have some time tomorrow, I'll run some automated measurements of DC out voltage into a high Z load versus RF voltage. Jack K8ZOA www.cliftonlaboratories.com Nick-WA5BDU wrote: > It's common to recommend a Schottky as a replacement for the 1N34A. > I've done it myself. That's why I was surprised to find this web page - > > http://www.cliftonlaboratories.com/diode_vf_vs_if.htm > > where this guy discovers that the Schottky diode (1N5711, to be > specific) can show some pretty high forward voltage drops. Turns out > that the low drop we're all familiar with exists at quite low values > of forward current -- less than 1 mA. At ~2 mA is a sort of > breakpoint where Vf begins to increase at a faster rate than in the > silicon or the germanium diodes. By ~10 mA, the 1N5711 has the > highest forward voltage of all three. Quite an eye-opener! > > You might think that for the RF probe application, forward current > will be small. Maybe it is. But often times small average currents > are misleading if there's a short conduction angle (time). > > 72--Nick, WA5BDU > > --back to counting screws > > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Nick Kennedy
I've looked at three diode types today (Schottky, germanium and
silicon) to see how they might perform in a simple RF probe over the range 2-21 MHz. The details are at http://www.cliftonlaboratories.com/diodes_for_rf_probes.htm Rankings are (no surprises here) germanium first, Schottky in the middle and silicon bringing up the rear. Jack K8ZOA www.cliftonlaboratories.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Diode Selection for RF Probes
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Jack
It's really interesting to read the articles on your site. In QST recently there was an article about a crystal set and a self-biased fet was used instead of a diode and I think it was said that this gave a higher output. It would be interesting to see how that would rank in your tests and might prove useful in a probe. David G3UNA ----- Original Message ----- From: "Jack Smith" <[hidden email]> To: "Nick-WA5BDU" <[hidden email]> Cc: <[hidden email]> Sent: Saturday, July 12, 2008 12:22 AM Subject: [Elecraft] Diode Selection for RF Probes > I've looked at three diode types today (Schottky, germanium and silicon) > to see how they might perform in a simple RF probe over the range 2-21 > MHz. > > The details are at > http://www.cliftonlaboratories.com/diodes_for_rf_probes.htm > > Rankings are (no surprises here) germanium first, Schottky in the middle > and silicon bringing up the rear. > > Jack K8ZOA > www.cliftonlaboratories.com > > >> > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by OE5CSP-Chris
Hi,
Thanks for your help.I need the RF-probe for my K3, which is still deaf and it seems other hams are having similar problems.I hope to get the missing parts next week... 73-Chris-OE5CSP K2#2447 K3#1073 |
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Is the K3 capable of using an RF probe similar to the K2? Do you get an RF
probe with the K3 like you do with the K2? Can one be added to the order if not? How much is it? 73, Jim KG0KP ----- Original Message ----- From: "OE5CSP-Chris" <[hidden email]> To: <[hidden email]> Sent: Sunday, July 13, 2008 7:23 AM Subject: Re: [Elecraft] 1N34A-Diode,RF probe > > Hi, > > Thanks for your help.I need the RF-probe for my K3, which is still deaf and > it seems other hams are having similar problems.I hope to get the missing > parts next week... > > > 73-Chris-OE5CSP > > K2#2447 > K3#1073 > -- > View this message in context: > Sent from the Elecraft mailing list archive at Nabble.com. > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Speaking from personal experience you have to order the RF Probe kit
separately. It is the one that comes with the K2 and it costs $10.00 as of 3 weeks ago. Ed W0SD _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by hf4me
<quote author="KG0KP"> Is the K3 capable of using an RF probe similar to the K2? Do you get an RF probe with the K3 like you do with the K2? Can one be added to the order if not? How much is it? 73, Jim KG0KP Jim, Elecraft sent me the diagram of the RF-probe in an e-mail.If you want to have it, just send me mail.It is not included with the K3. 73,Chris-OE5CSP |
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Did you ever get a chance to measure the voltage at pins 6 and 8 on your
connection to the Reference board? On Mon, 2008-07-14 at 01:15 -0700, OE5CSP-Chris wrote: > > > Is the K3 capable of using an RF probe similar to the K2? Do you get an RF > probe with the K3 like you do with the K2? Can one be added to the order if > not? How much is it? > > 73, Jim KG0KP > > Jim, > > Elecraft sent me the diagram of the RF-probe in an e-mail.If you want to > have it, just send me mail.It is not included with the K3. > > > > 73,Chris-OE5CSP _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by hf4me
The same RF probe can be handy doing some troubleshooting if it ever becomes
necessary. The K3 does not come with one as its not an essential/integral part of the radio as it is in building the K2. An inexpensive kit is availble through Elecraft by contacting their sales department. ------------------------- 73, Greg - AB7R Whidbey Island WA NA-065 On Sun Jul 13 10:39 , "Jim Miller" sent: >Is the K3 capable of using an RF probe similar to the K2? Do you get an RF >probe with the K3 like you do with the K2? Can one be added to the order if >not? How much is it? > >73, Jim KG0KP > >----- Original Message ----- >From: "OE5CSP-Chris" [hidden email]> >To: [hidden email]> >Sent: Sunday, July 13, 2008 7:23 AM >Subject: Re: [Elecraft] 1N34A-Diode,RF probe > > >> >> Hi, >> >> Thanks for your help.I need the RF-probe for my K3, which is still deaf >and >> it seems other hams are having similar problems.I hope to get the missing >> parts next week... >> >> >> 73-Chris-OE5CSP >> >> K2#2447 >> K3#1073 >> -- >> View this message in context: >http://n2.nabble.com/1N34A-Diode%2CRF-probe-tp472637p518053.html >> Sent from the Elecraft mailing list archive at Nabble.com. >> >> _______________________________________________ >> Elecraft mailing list >> Post to: [hidden email] >> You must be a subscriber to post to the list. >> Subscriber Info (Addr. Change, sub, unsub etc.): >> http://mailman.qth.net/mailman/listinfo/elecraft >> >> Help: http://mailman.qth.net/subscribers.htm >> Elecraft web page: http://www.elecraft.com >> > >_______________________________________________ >Elecraft mailing list >Post to: [hidden email] >You must be a subscriber to post to the list. >Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > >Help: http://mailman.qth.net/subscribers.htm >Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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This post was updated on .
In reply to this post by OE5CSP-Chris
Is it possible 1N34A diode to be used for detecting GSM waves?
I want to make GSM stick which flashes when GSM transmit. Like this one: http://youtu.be/CNJVhzOjWgU |
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