k2 bnc connector
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Hello
Has anyone had any trouble with the bnc antenna connector on a K2? Mine doesn't make contact with the antenna coax all the time. I can tell by the receiver noise when it looses contact. I think it is probably doing that when I am transmitting, but I have no way to tell except the swr goes out is sight. I have tried several of the bnc to pl239 adaptors and have the same problem with all of them. Has anyone ever changed out the antenna receptical from the bnc to a so239? This loosing contact with the antenna while I am transmitting can't be very good on the K2 final amps. Any info will be appreciated. 73 Scott N5SM _______________________________________________ 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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Scott,
IMHO, changing from a BNC to a UHF jack (SO239) would be a step backwards. The SO239 requires that the connector be tight to produce a reliable connection, BNC and type N connectors do not. If the BNC connector on the K2 has been abused, it can lose contact at the center pin, so you may have a valid point, but replacing it with a new BNC connector should solve the problem - if yo want to get really fancy, replace it with a type N connector. 73, Don W3FPR Scott McDowell wrote: > Hello > > Has anyone had any trouble with the bnc antenna connector on a K2? > Mine doesn't make contact with the antenna coax all the time. I can tell > by the receiver noise when it looses contact. I think it is probably doing > that when I am transmitting, but I have no way to tell except the swr goes > out is sight. I have tried several of the bnc to pl239 adaptors and have the > same problem with all of them. > Has anyone ever changed out the antenna receptical from the bnc to a > so239? This loosing contact with the antenna while I am transmitting can't > be very good on the K2 final amps. > Any info will be appreciated. > 73 > Scott N5SM > _______________________________________________ > 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 > > No virus found in this incoming message. > Checked by AVG - http://www.avg.com > Version: 8.0.138 / Virus Database: 270.5.12/1595 - Release Date: 8/6/2008 8:23 AM > > > > 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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Oak Hills Research sells kit containing two very nice, quality
BNC chassis-mount female connectors with gold-plated pins. The kit also comes with mounting plates and hardware to install them in standard SO-239 holes. It's their part number OP-SB2 and sells for $7.50 for a pack of two. I used these kits when I built my K3 to replace the two SO-239's supplied with the kit, and also on my WM-2 wattmeter. 73! Ken Kopp - K0PP [hidden email] _______________________________________________ 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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Most hams know that the standard BNC (not the mini version) should handle 200-300 watts and not be pushed higher, altho likely will go higher for some time. The So-239 is often rated at a Kilowatt of RF but clearly takes double that in many many shacks. However, at about 6 KW with a small SWR, the SO-239 will begin to arc the pin to shield. The big one that looks something like a BNC, called an N, has many advantages including taking higher RF, presenting a lower SWR bump in the line, greater shielding of the shield line, and a nice twist and pull release removal method (or screw on versions, too). These are seen on antennas for 440 and above often (like Hustler). However, they are even harder to install/solder especially if u try to keep the O ring that resists water entry in place. Forget the SMA for ham RF applications. GL, and I mean, GL... Charles Harpole [hidden email] > From: [hidden email] > To: [hidden email] > Subject: [Elecraft] K2 bnc connector > Date: Thu, 7 Aug 2008 05:08:28 +0000 > > Oak Hills Research sells kit containing two very nice, quality > BNC chassis-mount female connectors with gold-plated pins. > The kit also comes with mounting plates and hardware to install > them in standard SO-239 holes. It's their part number OP-SB2 > and sells for $7.50 for a pack of two. > > I used these kits when I built my K3 to replace the two SO-239's > supplied with the kit, and also on my WM-2 wattmeter. > > 73! Ken Kopp - K0PP > [hidden email] > _______________________________________________ > 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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<<Most hams know that the standard BNC (not the mini
version) should handle 200-300 watts and not be pushed higher, altho likely will go higher for some time.>> The BNC, either 50 or 75 ohm, is dimensionally almost identical to the 50-ohm style type N connector. As a matter of fact we use BNC males with the locking ring removed as push on connectors to mate with 50 ohm N females. All we have to do is very slightly flare the BNC mating ground shell to increase pressure a bit on the inside of the N. The weak point is the cable with BNC's, not the connectors. The connectors, like a type N, will handle a few kilowatts into a matched load. <<The So-239 is often rated at a Kilowatt of RF but clearly takes double that in many many shacks. However, at about 6 KW with a small SWR, the SO-239 will begin to arc the pin to shield.>> We high-pot SO-239/PL-259 combos at 5,000 volts peak. A good connector properly installed will easily make that number. 5000*.707 is 3500 VRMS. That's 250kW into 50 ohms, so arcing is never the issue in a properly installed connector. They are current limited which is a heating problem, but will easily handle five times the current of a type N because the pin surface area is much larger. Whenever we install connectors we high pot them to be sure we have no stray strands or other problems. We flatly reject anything below 3.5 kV, but prefer to have 5kV or more. <The big one that looks something like a BNC, called an N, has many advantages including taking higher RF, presenting a lower SWR bump in the line, greater shielding of the shield line,>> I disagree Charlie. There is a HN we use in plasma and other high power high SWR applications, but a type N like the BNC is really a weak connector. The N is a glorified weather tight BNC. I'd never consider a type N at more than 1500 watts or especially into a high SWR. They are terrible for lightning and SWR related damage because they have very small center pins and very close internal spacing. The HN is much better if you want a reliable connector that is N style. That's all we use on high power plasma and medical. The impedance bump in a UHF is limited to an area about 1/2 inch long. The problem is all in the female, the male (like most males) is nearly perfect. You wind up with 1/2 inch of 30-45 ohm line section for every standard properly installed UHF connector pair. The general electrical rule is a moderately sensitive system like a communications system can have about 1 degree of bump at that SWR, so the UHF connector should be good up to lower UHF with problems unless you get too many in the system. This is why Motorola never had a problem with UHF connectors on VHF gear. As a matter of fact when I install hardline here I actually machine the N female ends and convert them to UHF females with Teflon insulation. We've had N's blow right apart in lighting hits, but the UHF connectors keep on ticking. For UHF weak signal I might consider an N, but they are unreliable at high power or with high SWR or lightning. At low power where a cable needs to be quickly disconnected a BNC is fine, but I'd never use them here for anything outside of the test bench or a radio that needs a quick disconnect. Ham manufacturers did the right thing by using a UHF connector. It was generally a smart move. 73 Tom _______________________________________________ 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 Scott McDowell-4
Scott,
Before changing it you should verify that your antenna coax is using a 50 ohm BNC. The center conductor of the 75 ohm ones is smaller and will give intermittent contact. 73 Kevin w9cf
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Kevin,
while this may be true for a type N-connector, this is definitely not the case for BNC connectors. The center conductor in a BNC-type connector is exactly the same for a 50 ohm and a 75 ohm version. The only difference is that a 50 ohm BNC has a teflon "shell" at the inside of the outer conductor ring while the 75 ohm version does not have this teflon shell. It's the teflon that causes the impedance difference, *not* the inner conductor diameter. 73 Glenn ON4WIX ----- Original Message ----- From: "w9cf" <[hidden email]> To: <[hidden email]> Sent: Thursday, August 07, 2008 10:03 PM Subject: Re: [Elecraft] k2 bnc connector > > Scott, > > Before changing it you should verify that your antenna coax is using a 50 > ohm BNC. > The center conductor of the 75 ohm ones is smaller and will give > intermittent contact. > > 73 Kevin w9cf > > > Scott McDowell-4 wrote: >> >> Hello >> >> Has anyone had any trouble with the bnc antenna connector on a K2? >> Mine doesn't make contact with the antenna coax all the time. I can tell >> by the receiver noise when it looses contact. I think it is probably >> doing >> that when I am transmitting, but I have no way to tell except the swr >> goes >> out is sight. I have tried several of the bnc to pl239 adaptors and have >> the >> same problem with all of them. >> Has anyone ever changed out the antenna receptical from the bnc to a >> so239? This loosing contact with the antenna while I am transmitting >> can't >> be very good on the K2 final amps. >> Any info will be appreciated. >> 73 >> Scott N5SM >> _______________________________________________ >> 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 >> >> > > -- > View this message in context: > http://n2.nabble.com/k2-bnc-connector-tp677440p679435.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 > > No virus found in this incoming message. > Checked by AVG - http://www.avg.com > Version: 8.0.138 / Virus Database: 270.5.12/1597 - Release Date: 7/08/2008 > 5:54 > > > _______________________________________________ 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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Glenn,
I apologize for the misinformation. You are absolutely right. I was thinking of N-connectors. 73 Kevin w9cf
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In reply to this post by W8JI
There was an earlier discussion on the list about the definition of
"Software-Defined Radio" and whether the K3 qualifies. The answer appears in W1ZR's "Getting on the air" column in the latest issue (September) of QST. The answer is that "SDR" does not necessarily imply open-source software. Proprietary software qualifies, as long as it can re-define the receive/transmit RF paths and be downloaded in the field. They specifically mention the K3 (and IC-7800, TS-2000, Orion and FT-2000) and even include a photo. So the oracle has spoken. Question resolved. :=) Al N1AL _______________________________________________ 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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SDR radios may come to be a problem for hams who live where there are tight gov regs on freqs rigs can cover because the argument is, if they can be programmed to lock out some bands, they can be brought back by software easily. Since virtually all radios in the future will be at least part SDR, woe is some. 73 Charles Harpole [hidden email] > From: [hidden email] > To: [hidden email] > Date: Wed, 13 Aug 2008 19:48:47 -0700 > Subject: [Elecraft] ARRL: K3 is SDR > > There was an earlier discussion on the list about the definition of > "Software-Defined Radio" and whether the K3 qualifies. The answer > appears in W1ZR's "Getting on the air" column in the latest issue > (September) of QST. > > The answer is that "SDR" does not necessarily imply open-source > software. Proprietary software qualifies, as long as it can re-define > the receive/transmit RF paths and be downloaded in the field. They > specifically mention the K3 (and IC-7800, TS-2000, Orion and FT-2000) > and even include a photo. > > So the oracle has spoken. Question resolved. :=) > > Al N1AL > > > _______________________________________________ > 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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Charles and all,
Perhaps you are right, but I'm not sure you are right. For one thing, most rigs of recent manufacture can be "opened up", either by software or by snipping a diode or two. The latter type is even easier to defeat than one controlled by software, at least for most, since you have to be somewhat technically astute about software to use that method. Snipping a diode isn't necessarily that difficult. Restrictive control for either type is pretty easy to overcome. But the real reason I suspect it won't be a problem is that apparently software controllable radios have already been approved just about everywhere I think. For example, the FT-1000MP Mark V can be opened up just by accessing the right menu. I guess that isn't exactly "software" control, but it's similar. You are using the rig's internal software to make the change as opposed to using a computer connection externally. Just my guess. Dave W7AQK ----- Original Message ----- From: "Charles Harpole" <[hidden email]> To: <[hidden email]>; <[hidden email]> Sent: Wednesday, August 13, 2008 11:02 PM Subject: [Elecraft] SDR and regs SDR radios may come to be a problem for hams who live where there are tight gov regs on freqs rigs can cover because the argument is, if they can be programmed to lock out some bands, they can be brought back by software easily. Since virtually all radios in the future will be at least part SDR, woe is some. 73 Charles Harpole [hidden email] > From: [hidden email] > To: [hidden email] > Date: Wed, 13 Aug 2008 19:48:47 -0700 > Subject: [Elecraft] ARRL: K3 is SDR > > There was an earlier discussion on the list about the > definition of > "Software-Defined Radio" and whether the K3 qualifies. The > answer > appears in W1ZR's "Getting on the air" column in the > latest issue > (September) of QST. > > The answer is that "SDR" does not necessarily imply > open-source > software. Proprietary software qualifies, as long as it > can re-define > the receive/transmit RF paths and be downloaded in the > field. They > specifically mention the K3 (and IC-7800, TS-2000, Orion > and FT-2000) > and even include a photo. > > So the oracle has spoken. Question resolved. :=) > > Al N1AL > > > _______________________________________________ > 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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