P3 Loss of signal
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Recently, I have noticed that after a switching bands or simple setting ideal for while just listing, my P3 & SVGA screen signals drop off to almost a flat line. After simply giving the IF BNC connector a light tap, everything returns to normal.
I replaced the IF jumper with a replacement unit from Elecraft sometime ago so I assume it is a good. Anyone else had a similar experience? Thanks, Bill |
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Bill,
You might want to try a different cable. You said it was replaced "sometime ago" - there was a spell of time when Elecraft had a batch of bad cables. That situation has now been corrected, but you may indeed have 2 bad cables. The fact that things are restored when you tap the cable says that the cable is faulty. 73, Don W3FPR On 11/19/2013 6:02 PM, Bill W wrote: > Recently, I have noticed that after a switching bands or simple setting ideal > for while just listing, my P3 & SVGA screen signals drop off to almost a > flat line. After simply giving the IF BNC connector a light tap, everything > returns to normal. > I replaced the IF jumper with a replacement unit from Elecraft sometime ago > so I assume it is a good. > Anyone else had a similar experience? > Thanks, > Bill > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Bill W
Hi Don,
Thanks for the reply. Yes that crossed my mind but the cable I use now was suppose to be from the "new" batch. I called and got replacement from Elecraft Parts after earlier problem. I think this cable has been in use for better than a year or more and nothing has changed. I will switch cables as soon as I can find or make a new one. I was just curious if anyone else had a similar problem crop up. Thanks again, Bill - W0BBI |
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Bill,
Another issue with BNC connectors to take into account is that 50 ohm & 75 ohm BNC male connectors have a very slightly different diameter on the male center pin. The larger one (don't remember which one) can expand the female center socket. If you switch to the smaller version male after using the larger one, you may get an intermittent connection. You can tighten the female with a dental pick. We mixed connectors when TV stations switched from UHF to BNC for video. We found this issue years later! All BNC males are not the same. I make sure to use 50 ohm BNC connectors in the ham station for this reason. 73 George AI4VZ -------------------------------------------------- From: "Bill W" <[hidden email]> Sent: Tuesday, November 19, 2013 9:56 PM To: <[hidden email]> Subject: Re: [Elecraft] P3 Loss of signal Hi Don, Thanks for the reply. Yes that crossed my mind but the cable I use now was suppose to be from the "new" batch. I called and got replacement from Elecraft Parts after earlier problem. I think this cable has been in use for better than a year or more and nothing has changed. I will switch cables as soon as I can find or make a new one. I was just curious if anyone else had a similar problem crop up. Thanks again, Bill - W0BBI -- View this message in context: http://elecraft.365791.n2.nabble.com/P3-Loss-of-signal-tp7580978p7580989.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Bill W
Bill,
Another issue with BNC connectors to take into account is that 50 ohm & 75 ohm BNC male connectors have a very slightly different diameter on the male center pin. The larger one (don't remember which one) can expand the female center socket. If you switch to the smaller version male after using the larger one, you may get an intermittent connection. You can tighten the female with a dental pick. We mixed connectors when TV stations switched from UHF to BNC for video. We found this issue years later! All BNC males are not the same. I make sure to use 50 ohm BNC connectors in the ham station for this reason. 73 George AI4VZ -------------------------------------------------- From: "Bill W" <[hidden email]> Sent: Tuesday, November 19, 2013 9:56 PM To: <[hidden email]> Subject: Re: [Elecraft] P3 Loss of signal Hi Don, Thanks for the reply. Yes that crossed my mind but the cable I use now was suppose to be from the "new" batch. I called and got replacement from Elecraft Parts after earlier problem. I think this cable has been in use for better than a year or more and nothing has changed. I will switch cables as soon as I can find or make a new one. I was just curious if anyone else had a similar problem crop up. Thanks again, Bill - W0BBI -- View this message in context: http://elecraft.365791.n2.nabble.com/P3-Loss-of-signal-tp7580978p7580989.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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When comparing similar size cables or connectors, the one with the smaller
inner diameter will be the highest impedance. 73, Charlie k3ICH ----- Original Message ----- From: "George Danner" <[hidden email]> To: <[hidden email]> Sent: Wednesday, November 20, 2013 8:34 AM Subject: Re: [Elecraft] P3 Loss of signal > Bill, > Another issue with BNC connectors to take into account is that 50 ohm & 75 > ohm BNC male connectors have a very slightly different diameter on the > male > center pin. The larger one (don't remember which one) can expand the > female > center socket. If you switch to the smaller version male after using the > larger one, you may get an intermittent connection. You can tighten the > female with a dental pick. > We mixed connectors when TV stations switched from UHF to BNC for video. > We > found this issue years later! All BNC males are not the same. I make sure > to > use 50 ohm BNC connectors in the ham station for this reason. > 73 > George > AI4VZ > > -------------------------------------------------- > From: "Bill W" <[hidden email]> > Sent: Tuesday, November 19, 2013 9:56 PM > To: <[hidden email]> > Subject: Re: [Elecraft] P3 Loss of signal > > Hi Don, > Thanks for the reply. Yes that crossed my mind but the cable I use now was > suppose to be from the "new" batch. I called and got replacement from > Elecraft Parts after earlier problem. I think this cable has been in use > for > better than a year or more and nothing has changed. I will switch cables > as > soon as I can find or make a new one. I was just curious if anyone else > had > a similar problem crop up. > Thanks again, > Bill - W0BBI > > > > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/P3-Loss-of-signal-tp7580978p7580989.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Bill W
Hi George, Charlie
Thanks George as your comment about BNC center pins was a new learning. Since I was using cables from Elecraft, that would have never crossed my mind. I did change cables and all appears to be back to normal for now. I checked the center pin to pin on the cable I removed and it is loose on one end. Can't imagine what caused it to just fail. Now it is just matter of getting a good permanent replacement cable. Thanks Charlie for the tip as well. Thanks again, Bill - W0BBI |
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In reply to this post by Charlie T, K3ICH
Charlie,
Your information about BNC pin size diameter used to be true but not so anymore. These days the BNC center pin size is the same for 50 and 75 ohms. The quote below is from 2004 so this change took place a long time ago. See: http://forum.allaboutcircuits.com/newsgroups/viewtopic.php?p=157284 73 de Brian/K3KO PostPosted: Wed Aug 11, 2004 11:25 pm Post subject: Re: BNC centre pin size for 75 and 50 ohm sockets "Fred" <[hidden email]> schrieb im Newsbeitrag news:4119d8e2$0$206$[hidden email]... Quote: I have access to some 50 ohm BNC sockets. However it must mate to a 75 ohm plug. Since we are talking about video frequencies here I'm not worried about mismatches etc. What are the dimensional differences between the 50 and 75 ohm sockets? Can anyone point to dimensioned drawings of both types including pin size etc? Hello Fred, I tried with Google: bnc 75 50 difference The first hit. http://www.levitonvoicedata.com/support/technotes/tech_note_detail.asp?tnID=175 Original text from this page follows. --- begin --- Difference between 50 Ohm and 75 Ohm BNC Connectors What are the physical differences between 50 Ohm BNC connectors and 75 Ohm BNC connectors? There are a few physical differences. The 75 Ohm plug’s center pin has the same diameter in the rear as in the front mating interface area. Whereas, the 50 Ohm plug’s center pin has a thicker diameter in the rear area where it is crimped. Both plugs have the same pin size in the mating area. Regarding the dielectric on each, the 75 Ohm connector’s dielectric is made of Teflon which has higher impedance properties than Delrin. The 50 Ohm connector’s dielectric is made of Delrin. Finally, the main physical difference is that the 75 Ohm plug does not have extended dielectric around its outer spring fingers. On 11/20/2013 14:59, Charlie T, K3ICH wrote: > When comparing similar size cables or connectors, the one with the > smaller inner diameter will be the highest impedance. > > 73, Charlie k3ICH > > ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2247 / Virus Database: 3629/6351 - Release Date: 11/20/13 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Does that mean they're interchangeable?
Chas ----- Original Message ----- From: "Brian Alsop" <[hidden email]> To: <[hidden email]> Sent: Wednesday, November 20, 2013 10:49 AM Subject: Re: [Elecraft] P3 Loss of signal Charlie, Your information about BNC pin size diameter used to be true but not so anymore. These days the BNC center pin size is the same for 50 and 75 ohms. The quote below is from 2004 so this change took place a long time ago. See: http://forum.allaboutcircuits.com/newsgroups/viewtopic.php?p=157284 73 de Brian/K3KO PostPosted: Wed Aug 11, 2004 11:25 pm Post subject: Re: BNC centre pin size for 75 and 50 ohm sockets "Fred" <[hidden email]> schrieb im Newsbeitrag news:4119d8e2$0$206$[hidden email]... Quote: I have access to some 50 ohm BNC sockets. However it must mate to a 75 ohm plug. Since we are talking about video frequencies here I'm not worried about mismatches etc. What are the dimensional differences between the 50 and 75 ohm sockets? Can anyone point to dimensioned drawings of both types including pin size etc? ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I would have thought not, physically in terms of size yes, but electrically not, since they are different impedance.
73 de David, M0XDF (K3 #174, P3 #108) -- A person usually has two reasons for doing something: a good reason and the real reason. -Thomas Carlyle, historian and essayist (1795-1881) On 20 Nov 2013, at 16:51, Charlie T, K3ICH wrote: > Does that mean they're interchangeable? > > Chas > > ----- Original Message ----- From: "Brian Alsop" <[hidden email]> > To: <[hidden email]> > Sent: Wednesday, November 20, 2013 10:49 AM > Subject: Re: [Elecraft] P3 Loss of signal > > > Charlie, > > Your information about BNC pin size diameter used to be true but not so anymore. > > These days the BNC center pin size is the same for 50 and 75 ohms. > The quote below is from 2004 so this change took place a long time ago. > See: > http://forum.allaboutcircuits.com/newsgroups/viewtopic.php?p=157284 > > 73 de Brian/K3KO > > PostPosted: Wed Aug 11, 2004 11:25 pm Post subject: Re: BNC centre pin size for 75 and 50 ohm sockets "Fred" <[hidden email]> schrieb im Newsbeitrag > news:4119d8e2$0$206$[hidden email]... > Quote: > I have access to some 50 ohm BNC sockets. However it must mate to a 75 > ohm > plug. Since we are talking about video frequencies here I'm not worried > about mismatches etc. > > What are the dimensional differences between the 50 and 75 ohm sockets? > > Can anyone point to dimensioned drawings of both types including pin size > etc? > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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The connector is so small with respect to a wavelength that the
impedance mismatch is of no concern, at least up through the VHF range. (Microwave is a different story.) Alan N1AL On 11/20/2013 09:00 AM, David Ferrington, M0XDF wrote: > I would have thought not, physically in terms of size yes, but electrically not, since they are different impedance. > 73 de David, M0XDF (K3 #174, P3 #108) > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Bill W
I just received a note from Howard K6IA in Customer Support at Elecraft.
He wanted to confirm my address so they can send me a replacement BNC cable. I did not request one nor had I contacted Elecraft about the issue directly. Can anyone name any other company that would take the initiative like that based on some exchanges on a reflector page? I think not! What an Outstanding Company Elecraft is, but of course, we all knew that already!!! Thanks Howard and thanks Elecraft!!! Bill-W0BBI |
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