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#21
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On 19/08/17 16:25, Rambo wrote:
On Sat, 19 Aug 2017 15:22:26 +0100, Brian Reay wrote: On 19/08/17 13:05, Ian Jackson wrote: In message , Gareth's Downstairs Computer writes On 19/08/2017 10:34, Jimbo wrote: sexes). when I was newly licensed and poor I used 75 ohm TV coax and belling lee connectors on HF and got away with it ....... And it was standard on 145MHz. (QQV03-10 anyone?) Actually, the original B&L connector is a pretty good 75 ohm match up to 1GHz and more. If I remember correctly, many 50 ohm BNCs are not so hot 500MHz. With 75 ohms, the problem is maintaining the structural return loss constant while having enough PTFE insulation to hold the pin in place. Some are only really good to around 200Mhz. Of course, for most purposes, both are usable to much higher frequencies. And mixable! Well, the B&L connectors are used for TV which covers well into the 100s of MHz. There is also the F connector, another 'cheap and cheerful' beast, used beyond 1GHz. I've not done any measurements but it obviously performs were enough for the task demanded of it. Both the B&L and F connector suffer (as do all connectors) problems if not fitted correctly but they are more prone to being 'bodged'. The B&L is, for example. prone to issues with poor braid bonding while the F connector, which uses the centre conductor as the pin, tend to be prone to the 'pin' not aligning etc. I believe the F connector is used in the US where we would, generally, expect to see a B&L connector. I believe the B&L is virtually unknown in the US. I was contacted by a US amateur some time back who had acquired a bit of UK kit (KW?) which had B&L sockets. He'd not seen them before. I sent him some plugs etc. Of course, there is nothing 'magic' about 50 ohm coax or the connectors we 'normally' use on our radios. If we were to stick to using 75 ohm coax and B&L connectors the world wouldn't end. Likewise, if you mixed 50 ohm and 75 ohm, while you may be able to measure a slight difference, chances are, in real terms, it wouldn't make much difference to the overall set up performance- at least unless you were doing something 'exotic'. You'd be more likely to notice the impact of a poorly fitted 'correct' connector in an all 50 ohm system. I tend to favour N types but I've not change all the connectors on my radios. The 'first' patch lead as whatever the radio needs on one end and required N type to connect to rest on the station on the other. The same for my mobile set ups. I also have a good collect of, quality, interseries, adaptors etc and a set of the correct connectors for my Bird power meters and dummy load etc. Through in a few home brew special adaptor leads for things I don't have adaptors for and I can interconnect virtually anything. Oh! has he finished? I dozed off for a moment there. That short attention span probably contributes to your problems studying and acquiring technical knowledge. That accounts for your problems with the Advanced Exam and lack of other qualifications. You should really have tried to seek help earlier, you could perhaps have improved it and achieved at least some worthwhile qualifications. |
#22
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On 19/08/2017 16:25, Rambo wrote:
Brian Reay wrote: Well, the B&L connectors are used for TV which covers well into the 100s of MHz. There is also the F connector, another 'cheap and cheerful' beast, used beyond 1GHz. I've not done any measurements but it obviously performs were enough for the task demanded of it. Both the B&L and F connector suffer (as do all connectors) problems if not fitted correctly but they are more prone to being 'bodged'. The B&L is, for example. prone to issues with poor braid bonding while the F connector, which uses the centre conductor as the pin, tend to be prone to the 'pin' not aligning etc. I believe the F connector is used in the US where we would, generally, expect to see a B&L connector. I believe the B&L is virtually unknown in the US. I was contacted by a US amateur some time back who had acquired a bit of UK kit (KW?) which had B&L sockets. He'd not seen them before. I sent him some plugs etc. Of course, there is nothing 'magic' about 50 ohm coax or the connectors we 'normally' use on our radios. If we were to stick to using 75 ohm coax and B&L connectors the world wouldn't end. Likewise, if you mixed 50 ohm and 75 ohm, while you may be able to measure a slight difference, chances are, in real terms, it wouldn't make much difference to the overall set up performance- at least unless you were doing something 'exotic'. You'd be more likely to notice the impact of a poorly fitted 'correct' connector in an all 50 ohm system. I tend to favour N types but I've not change all the connectors on my radios. The 'first' patch lead as whatever the radio needs on one end and required N type to connect to rest on the station on the other. The same for my mobile set ups. I also have a good collect of, quality, interseries, adaptors etc and a set of the correct connectors for my Bird power meters and dummy load etc. Through in a few home brew special adaptor leads for things I don't have adaptors for and I can interconnect virtually anything. Oh! has he finished? I dozed off for a moment there. It's the sledgehammer and nut syndrome, rather like using a VNA to set up an antenna when the distant station couldn't tell the difference between the results for that and using a 20p light bulb to do the same thing. -- Spike |
#23
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On Sat, 19 Aug 2017 16:53:49 +0100, "Jimbo"
wrote: "Rambo" wrote in message .. . On Sat, 19 Aug 2017 15:35:41 +0100, "Jimbo" wrote: "Ian Jackson" wrote in message ... In message , Gareth's Downstairs Computer writes On 19/08/2017 10:34, Jimbo wrote: sexes). when I was newly licensed and poor I used 75 ohm TV coax and belling lee connectors on HF and got away with it ....... And it was standard on 145MHz. (QQV03-10 anyone?) Actually, the original B&L connector is a pretty good 75 ohm match up to 1GHz and more. If I remember correctly, many 50 ohm BNCs are not so hot 500MHz. With 75 ohms, the problem is maintaining the structural return loss constant while having enough PTFE insulation to hold the pin in place. Some are only really good to around 200Mhz. Of course, for most purposes, both are usable to much higher frequencies. And mixable! I got a load of weird connectors and adaptors from a guy that worked at the sub base at New London in 1979 ...still using them ...... Type 43 connector? no idea ... oh was that a submarine joke? .... No it's a coax connector http://www.servicepower.co.uk/catego...43-connectors/ |
#24
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On Sat, 19 Aug 2017 18:06:12 +0100, Brian Reay wrote:
On 19/08/17 16:25, Rambo wrote: On Sat, 19 Aug 2017 15:22:26 +0100, Brian Reay wrote: On 19/08/17 13:05, Ian Jackson wrote: In message , Gareth's Downstairs Computer writes On 19/08/2017 10:34, Jimbo wrote: sexes). when I was newly licensed and poor I used 75 ohm TV coax and belling lee connectors on HF and got away with it ....... And it was standard on 145MHz. (QQV03-10 anyone?) Actually, the original B&L connector is a pretty good 75 ohm match up to 1GHz and more. If I remember correctly, many 50 ohm BNCs are not so hot 500MHz. With 75 ohms, the problem is maintaining the structural return loss constant while having enough PTFE insulation to hold the pin in place. Some are only really good to around 200Mhz. Of course, for most purposes, both are usable to much higher frequencies. And mixable! Well, the B&L connectors are used for TV which covers well into the 100s of MHz. There is also the F connector, another 'cheap and cheerful' beast, used beyond 1GHz. I've not done any measurements but it obviously performs were enough for the task demanded of it. Both the B&L and F connector suffer (as do all connectors) problems if not fitted correctly but they are more prone to being 'bodged'. The B&L is, for example. prone to issues with poor braid bonding while the F connector, which uses the centre conductor as the pin, tend to be prone to the 'pin' not aligning etc. I believe the F connector is used in the US where we would, generally, expect to see a B&L connector. I believe the B&L is virtually unknown in the US. I was contacted by a US amateur some time back who had acquired a bit of UK kit (KW?) which had B&L sockets. He'd not seen them before. I sent him some plugs etc. Of course, there is nothing 'magic' about 50 ohm coax or the connectors we 'normally' use on our radios. If we were to stick to using 75 ohm coax and B&L connectors the world wouldn't end. Likewise, if you mixed 50 ohm and 75 ohm, while you may be able to measure a slight difference, chances are, in real terms, it wouldn't make much difference to the overall set up performance- at least unless you were doing something 'exotic'. You'd be more likely to notice the impact of a poorly fitted 'correct' connector in an all 50 ohm system. I tend to favour N types but I've not change all the connectors on my radios. The 'first' patch lead as whatever the radio needs on one end and required N type to connect to rest on the station on the other. The same for my mobile set ups. I also have a good collect of, quality, interseries, adaptors etc and a set of the correct connectors for my Bird power meters and dummy load etc. Through in a few home brew special adaptor leads for things I don't have adaptors for and I can interconnect virtually anything. Oh! has he finished? I dozed off for a moment there. That short attention span probably contributes to your problems studying and acquiring technical knowledge. That accounts for your problems with the Advanced Exam and lack of other qualifications. You should really have tried to seek help earlier, you could perhaps have improved it and achieved at least some worthwhile qualifications. Perhaps if you should refrain from your self indulgent monologues and also take a break from fretting about others, and actually post something of interest, you wouldn't come across as such a dull crushing repetitive bore. |
#25
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![]() "Rambo" wrote in message ... On Sat, 19 Aug 2017 18:06:12 +0100, Brian Reay wrote: On 19/08/17 16:25, Rambo wrote: On Sat, 19 Aug 2017 15:22:26 +0100, Brian Reay wrote: On 19/08/17 13:05, Ian Jackson wrote: In message , Gareth's Downstairs Computer writes On 19/08/2017 10:34, Jimbo wrote: sexes). when I was newly licensed and poor I used 75 ohm TV coax and belling lee connectors on HF and got away with it ....... And it was standard on 145MHz. (QQV03-10 anyone?) Actually, the original B&L connector is a pretty good 75 ohm match up to 1GHz and more. If I remember correctly, many 50 ohm BNCs are not so hot 500MHz. With 75 ohms, the problem is maintaining the structural return loss constant while having enough PTFE insulation to hold the pin in place. Some are only really good to around 200Mhz. Of course, for most purposes, both are usable to much higher frequencies. And mixable! Well, the B&L connectors are used for TV which covers well into the 100s of MHz. There is also the F connector, another 'cheap and cheerful' beast, used beyond 1GHz. I've not done any measurements but it obviously performs were enough for the task demanded of it. Both the B&L and F connector suffer (as do all connectors) problems if not fitted correctly but they are more prone to being 'bodged'. The B&L is, for example. prone to issues with poor braid bonding while the F connector, which uses the centre conductor as the pin, tend to be prone to the 'pin' not aligning etc. I believe the F connector is used in the US where we would, generally, expect to see a B&L connector. I believe the B&L is virtually unknown in the US. I was contacted by a US amateur some time back who had acquired a bit of UK kit (KW?) which had B&L sockets. He'd not seen them before. I sent him some plugs etc. Of course, there is nothing 'magic' about 50 ohm coax or the connectors we 'normally' use on our radios. If we were to stick to using 75 ohm coax and B&L connectors the world wouldn't end. Likewise, if you mixed 50 ohm and 75 ohm, while you may be able to measure a slight difference, chances are, in real terms, it wouldn't make much difference to the overall set up performance- at least unless you were doing something 'exotic'. You'd be more likely to notice the impact of a poorly fitted 'correct' connector in an all 50 ohm system. I tend to favour N types but I've not change all the connectors on my radios. The 'first' patch lead as whatever the radio needs on one end and required N type to connect to rest on the station on the other. The same for my mobile set ups. I also have a good collect of, quality, interseries, adaptors etc and a set of the correct connectors for my Bird power meters and dummy load etc. Through in a few home brew special adaptor leads for things I don't have adaptors for and I can interconnect virtually anything. Oh! has he finished? I dozed off for a moment there. That short attention span probably contributes to your problems studying and acquiring technical knowledge. That accounts for your problems with the Advanced Exam and lack of other qualifications. You should really have tried to seek help earlier, you could perhaps have improved it and achieved at least some worthwhile qualifications. Perhaps if you should refrain from your self indulgent monologues and also take a break from fretting about others, and actually post something of interest, you wouldn't come across as such a dull crushing repetitive bore. he is isn't he ...... |
#26
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![]() "Rambo" wrote in message ... On Sat, 19 Aug 2017 16:53:49 +0100, "Jimbo" wrote: "Rambo" wrote in message . .. On Sat, 19 Aug 2017 15:35:41 +0100, "Jimbo" wrote: "Ian Jackson" wrote in message ... In message , Gareth's Downstairs Computer writes On 19/08/2017 10:34, Jimbo wrote: sexes). when I was newly licensed and poor I used 75 ohm TV coax and belling lee connectors on HF and got away with it ....... And it was standard on 145MHz. (QQV03-10 anyone?) Actually, the original B&L connector is a pretty good 75 ohm match up to 1GHz and more. If I remember correctly, many 50 ohm BNCs are not so hot 500MHz. With 75 ohms, the problem is maintaining the structural return loss constant while having enough PTFE insulation to hold the pin in place. Some are only really good to around 200Mhz. Of course, for most purposes, both are usable to much higher frequencies. And mixable! I got a load of weird connectors and adaptors from a guy that worked at the sub base at New London in 1979 ...still using them ...... Type 43 connector? no idea ... oh was that a submarine joke? .... No it's a coax connector http://www.servicepower.co.uk/catego...43-connectors/ no don't think I have any of those ...... |
#27
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On Sat, 19 Aug 2017 20:33:52 +0100, "Jimbo"
wrote: "Rambo" wrote in message .. . On Sat, 19 Aug 2017 16:53:49 +0100, "Jimbo" wrote: "Rambo" wrote in message ... On Sat, 19 Aug 2017 15:35:41 +0100, "Jimbo" wrote: "Ian Jackson" wrote in message ... In message , Gareth's Downstairs Computer writes On 19/08/2017 10:34, Jimbo wrote: sexes). when I was newly licensed and poor I used 75 ohm TV coax and belling lee connectors on HF and got away with it ....... And it was standard on 145MHz. (QQV03-10 anyone?) Actually, the original B&L connector is a pretty good 75 ohm match up to 1GHz and more. If I remember correctly, many 50 ohm BNCs are not so hot 500MHz. With 75 ohms, the problem is maintaining the structural return loss constant while having enough PTFE insulation to hold the pin in place. Some are only really good to around 200Mhz. Of course, for most purposes, both are usable to much higher frequencies. And mixable! I got a load of weird connectors and adaptors from a guy that worked at the sub base at New London in 1979 ...still using them ...... Type 43 connector? no idea ... oh was that a submarine joke? .... No it's a coax connector http://www.servicepower.co.uk/catego...43-connectors/ no don't think I have any of those ...... I've seen too bloody many !!!! |
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