Path: ...!3.eu.feeder.erje.net!feeder.erje.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
From: Ian Jackson <ianREMOVETHISjackson@g3ohx.co.uk>
Newsgroups: sci.electronics.design,sci.electronics.repair
Subject: Re: Francophones
Date: Mon, 23 Dec 2024 15:22:24 +0000
Lines: 41
Message-ID: <Oi4e+cFwAYanFw0d@brattleho.plus.com>
References: <84fbmj56f92g7uspk4h5e04qj1vgri925o@4ax.com>
 <1r4vq2s.1tmc4wm1iuvgp4N%liz@poppyrecords.invalid.invalid>
 <tenbmjt25re7vpgusummh2mjqvgofmnnk4@4ax.com> <vk4svg$3ls1l$1@dont-email.me>
 <ll0cmjh5dto2fp168a7f1b3aap5vvj1rso@4ax.com>
 <1r4wrcj.5sbtfti811qyN%liz@poppyrecords.invalid.invalid>
 <95idmjpun3fqc5d4ud98havpjs4qo2iqnk@4ax.com> <vk78c3$75og$1@dont-email.me>
 <iqaemjt97dl6dkkm6cjlg4smkp96gr31fr@4ax.com> <vk7bs3$7n60$1@dont-email.me>
 <i7demj9r32kvi2hsh2lqpim4vs6c4a8j4g@4ax.com>
 <slrnvmegbv.1gks.trepidation@vps.jonz.net>
 <m7kemj1c5knrgt5l4nes3s1fsrbubcu62c@4ax.com>
 <1r4ynfn.b59oq9u83h8qN%liz@poppyrecords.invalid.invalid>
 <vka5ni$r5r3$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain;charset=us-ascii;format=flowed
X-Trace: individual.net GbT1Tq9ufPuaDflNXoPUewQMpc/Vb+LDefjb81lF+FB5di7HH3
X-Orig-Path: g3ohx.co.uk!ianREMOVETHISjackson
Cancel-Lock: sha1:ABwtSaFrCDss8WnuHQkETsTdT+Y= sha256:KRkDdF881vZyRDiLvNEX+ZdRMWfNqrvr+TBjELrxBTk=
User-Agent: Turnpike/6.07-S (<XlTqWap7KPDWaPCjsRGoeAF+yl>)
X-Antivirus: AVG (VPS 241223-2, 23/12/2024), Outbound message
X-Antivirus-Status: Clean
Bytes: 3338

In message <vka5ni$r5r3$1@dont-email.me>, piglet 
<erichpwagner@hotmail.com> writes
>Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
>> Cursitor Doom <cd@notformail.com> wrote:
>>
>>> On 21 Dec 2024 22:30:23 GMT, Allodoxaphobia <trepidation@example.net>
>>> wrote:
>>>
>>>> On Sat, 21 Dec 2024 21:37:59 +0000, Cursitor Doom wrote:
>>>>>> in series with your 50 Ohm source.
>>>>>
>>>>> Yes, but you know what a *bitch* it is to find a purely resistive 10
>>>>> ohms....
>>>>
>>>> Maybe just a length of nichrome wire?
>>>
>>> Still got parasitics. Avoiding them is a craft in itself.
>>
>> I wouldn't worry about the inductance of an ordianry 1/4 -Watt resistor
>> at the frequencies involved.  The only point where it might make any
>> difference is the VHF input and oscillator tuning - and I can't think
>> you need a great level of accuracy to align a domestic portable radio.
>>
>> It is even possible that they specified a 60-ohm sig gen because they
>> knew that most of the available ones would be near enough at either 50
>> or 75 0hms.   Another possibility would be to try to make you think you
>> had  to return the radio to their specialised service department for
>> repair.   The avarage radio shop (if there are any left) simply wouldn't
>> care and would use whatever they had on the shelf above the workbench.
>>
>60 ohms was a popular impedance for RF test gear in Europe in the 1950s and
>60s
>
For many purposes you can ignore the difference between the 50 and 75 
ohm impedances (and 60 if you ever come across any). However, be very 
aware only BNC 50 and 75 ohm connectors are mutually mechanically 
mateable (yes - they really are!). I don't know if any others that are.
-- 
Ian
Aims and ambitions are neither attainments nor achievements