XPost: uk.radio.amateur
From: kinvig.netta@ntlworld.com
"Rambo" wrote in message
news:rsvgpcpjru69ji8pc66csd1fptbfhlsnqr@4ax.com...
> 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 ......
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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