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UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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#42
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tv coax plugs
A quick calculation suggests that I have fitted at least 52,875 coax
plugs in my life, so far. Bill |
#43
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tv coax plugs
On Sat, 11 Jul 2015 20:18:23 +0100
Bill Wright wrote: A quick calculation suggests that I have fitted at least 52,875 coax plugs in my life, so far. Bill ... which, if all laid end-to-end, would reach to ?? -- Davey. |
#44
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tv coax plugs
Davey wrote:
On Sat, 11 Jul 2015 20:18:23 +0100 Bill Wright wrote: A quick calculation suggests that I have fitted at least 52,875 coax plugs in my life, so far. Bill .. which, if all laid end-to-end, would reach to ?? The mad house. Bill |
#45
Posted to uk.tech.digital-tv,uk.d-i-y
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tv coax plugs
In article , Bill Wright
scribeth thus A quick calculation suggests that I have fitted at least 52,875 coax plugs in my life, so far. Bill Do you get a card from Prince Phil to tell you to get a fecking move on to fit a few more;?... As he is won't to do;!... -- Tony Sayer |
#46
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tv coax plugs
If the cable has a generous quantity of braid (as it should have) this wont
work because there is not room inside the body to accept both clamp and braid. The correct way - based on pictures provided by Belling & Lee 50 years ago but recreated from memory - is as shown he http://i260.photobucket.com/albums/i...oto/tv/BL1.png http://i260.photobucket.com/albums/i...oto/tv/BL2.png http://i260.photobucket.com/albums/i...oto/tv/BL3.png It will probably be found easier to solder the centre pin first - this should make it easier to trim the braid with flush bladed cutters. The ring of braid compressed between the clamp and the insulator when the plug is assembled provides a true coaxial termination. Having misspent my younger years in the TV trade and having done quite a bit of rigging.. The number of times I've seen a Belling Lee plug fitted like that as it ought be around 10 or so. I swear blind those times were whilst I was working at Pye TVT on some studio OB equipment. The usual way was to wrap the braiding around the cable outer PVC and then as long as there was enough to fill up the collet clamp part then that was good enough. I did ask the tight barsteward for a soldering iron so as to solder them but he won't give us one and told us to nip the plug onto the inner core of the co-ax with side cutters which wasn't ideal. Some people never bothered with that even. As to the soldered or not it did work surprisingly l well if it wasn't soldered and it did work OK at UHF frequencies due to Capactive reactance being more effective at those frequencies rather than at VHF Band one and Three as there was never a strong ITV signal in the Cambridge area.. IMHO life would have been better if Belling Lee had never invented the damm thing anyway like the SCART plug and the abominable so called UHF plug the PL259 used in some PMR applications. In all the simple F plug was a much better idea. -- Tony Sayer |
#47
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tv coax plugs
In message , Bill Wright
writes A quick calculation suggests that I have fitted at least 52,875 coax plugs in my life, so far. As they say, "Practice makes perfect". -- Ian |
#48
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tv coax plugs
On Sat, 11 Jul 2015 17:12:52 +0100, Terry Casey
wrote: In article , says... It's a commonly held view given that feeder losses are so much greater at UHF, but it's wrong. How about reading the manufacturers tables? eg: URM43. 100MHz loss 13dB/100m 600MHz 34 URM67 50 MHz 4.5 800 MHz 18 Note sure if that adds anything... he just said that the feeder losses are higher at UHF, but that does not necessarily mean that termination losses are as well. There are two issues here and it important to address them both. The original, before it was selectively quoted, was: In article , says... It's a commonly held view given that feeder losses are so much greater at UHF, but it's wrong. Even if it's open circuit at DC there will still be a few picofarads of capacitance, and capacitive reactance decreases as the frequency increases. The first part is very obviously wrong, as has been already been said. I dont't think it is Terry, let me explain again. I was replying to charles who said: I'd expect far greater losses from an un-soldered joint at Band V I replied It's a commonly held view given that feeder losses are so much greater at UHF, but it's wrong. Apart from a missing comma after "view", I stand by what I said. Surley my use of the word "given" shows that I conceed that the statement that follows is true, ie cable losses are much higher at UHF (than at VHF). The point I was making is that an oxidised coaxial inner inserted into a coaxial plug may well be open circuit as far as DC is concerned, but the capacitor so formed (I would estimate 5-10pF) will, acording to the equasion 1 / 2*pi*f*C, have progressivly lower Xc (expressed in Ohms) as the frequency increases. Such a termination will therefore contribute a fraction of the attenuation at 500MHz than it would at 50MHz (to use my origanal comparason between Band IV and Band I). -- Graham. %Profound_observation% |
#49
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tv coax plugs
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#50
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tv coax plugs
On 11/07/2015 17:12, Terry Casey wrote:
In article , says... It's a commonly held view given that feeder losses are so much greater at UHF, but it's wrong. How about reading the manufacturers tables? eg: URM43. 100MHz loss 13dB/100m 600MHz 34 URM67 50 MHz 4.5 800 MHz 18 Note sure if that adds anything... he just said that the feeder losses are higher at UHF, but that does not necessarily mean that termination losses are as well. There are two issues here and it important to address them both. The original, before it was selectively quoted, was: In article , says... It's a commonly held view given that feeder losses are so much greater at UHF, but it's wrong. Even if it's open circuit at DC there will still be a few picofarads of capacitance, and capacitive reactance decreases as the frequency increases. The first part is very obviously wrong, as has been already been said. Its not thought ;-) everyone keeps misreading it! If one assembles the bits it effectively says: "I'd expect far greater losses from an un-soldered joint at Band V" To which Graham in effect replied: "It's a commonly held view, but it's wrong." What seems to have got everyone's knickers in a twist is the added comment " *given* that feeder losses are so much greater at UHF," (my emphasis on "given") - i.e. he is acknowledging that the feeder looses will be much higher, but this is a point unrelated to the effect of frequency on poor connections (which will better "jump" small open circuits due to the lower reactance of the capacitor formed) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#51
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tv coax plugs
On 11/07/2015 20:55, tony sayer wrote:
IMHO life would have been better if Belling Lee had never invented the damm thing anyway like the SCART plug and the abominable so called UHF plug the PL259 used in some PMR applications. In all the simple F plug was a much better idea. I have seen loads of BL plugs with the inner unsoldered - but a length of inner left protruding from the centre pin of the plug. In effect making it behave somewhat like a F connector with the co-az itself doing the final connection. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#52
Posted to uk.tech.digital-tv,uk.d-i-y
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tv coax plugs
En el artículo , Bill Wright
escribió: A quick calculation suggests that I have fitted at least 52,875 coax plugs in my life, so far. I was impressed with the speed at which an aerial fitter fitted the plug. Mind you, he had the proper tool for stripping the end of the cable - it cut the outer insulation, the braid/foil, and the inner insulation all to the right length in one go. -- (\_/) (='.'=) (")_(") |
#53
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tv coax plugs
On Mon, 13 Jul 2015 09:19:03 +0100
Mike Tomlinson wrote: En el artÃ*culo , Bill Wright escribió: A quick calculation suggests that I have fitted at least 52,875 coax plugs in my life, so far. I was impressed with the speed at which an aerial fitter fitted the plug. Mind you, he had the proper tool for stripping the end of the cable - it cut the outer insulation, the braid/foil, and the inner insulation all to the right length in one go. Yeah, that's cheating. It's only valid if done with a blunt penknife. This is, after all, a D-I-Y group. -- Davey. |
#54
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tv coax plugs
John Rumm wrote:
I have seen loads of BL plugs with the inner unsoldered - but a length of inner left protruding from the centre pin of the plug. In effect making it behave somewhat like a F connector with the co-az itself doing the final connection. That is often because the inner moves along the cable a bit, sometimes. And it is unlikely that the protruding inner will contact the inner connector of the socket, unless it is very bent. Bill |
#55
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tv coax plugs
Mike Tomlinson wrote:
En el artículo , Bill Wright escribió: A quick calculation suggests that I have fitted at least 52,875 coax plugs in my life, so far. I was impressed with the speed at which an aerial fitter fitted the plug. Mind you, he had the proper tool for stripping the end of the cable - it cut the outer insulation, the braid/foil, and the inner insulation all to the right length in one go. I would never do it like that. My coax plugs were lovingly hand-fitted. Bill |
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