UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Offered and Wanted Messages > Sets, Parts and Service Information Wanted (private buyers only, no swaps)

Notices

Sets, Parts and Service Information Wanted (private buyers only, no swaps) If you need help obtaining components, sets or equipment, post a message here. Private buyers only - no traders. No swaps.

Closed Thread
 
Thread Tools
Old 10th Jul 2018, 8:53 am   #1
'LIVEWIRE?'
Dekatron
 
'LIVEWIRE?''s Avatar
 
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 6,030
Question Co-ax Cable used in DAB Radios.

Admittedly I haven't checked all possible sources, but does anyone know of a supplier of lengths of the small-diameter RF Co-ax cable used in DAB radios to connect the telescopic aerial or 'F'-type socket to the RF Module?
'LIVEWIRE?' is online now  
Old 11th Jul 2018, 2:16 pm   #2
G8HQP Dave
Dekatron
 
Join Date: Sep 2008
Location: Solihull, West Midlands, UK.
Posts: 4,339
Default Re: Co-ax Cable used in DAB Radios.

Any miniature 75 ohm coax should do the job.
G8HQP Dave is offline  
Old 11th Jul 2018, 4:03 pm   #3
merlinmaxwell
Dekatron
 
merlinmaxwell's Avatar
 
Join Date: Jul 2008
Location: Maidenhead, Berkshire, UK.
Posts: 7,566
Default Re: Co-ax Cable used in DAB Radios.

I thought that DAB radios where 50 ohm.
__________________
Cats have staff, it's dogs that have owners.
merlinmaxwell is offline  
Old 11th Jul 2018, 4:28 pm   #4
michamoo
Hexode
 
michamoo's Avatar
 
Join Date: May 2006
Location: Cambridge, Cambs. UK.
Posts: 368
Default Re: Co-ax Cable used in DAB Radios.

Screened microphone cable would do well enough for that job.
__________________
If smoking is so bad for you, how come it cures kippers?
michamoo is offline  
Old 12th Jul 2018, 8:43 am   #5
'LIVEWIRE?'
Dekatron
 
'LIVEWIRE?''s Avatar
 
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 6,030
Default Re: Co-ax Cable used in DAB Radios.

I've now ordered a metre of miniature 50 ohm cable from an ebay supplier, but once in the past i did use a length of microphone cable for this purpose. The radio in question worked well with this substitute, although the impedance was probably wrong. Given that less than 5" of mic. cable was involved, the Z-mismatch was no doubt irrelevant anyway
'LIVEWIRE?' is online now  
Old 12th Jul 2018, 8:59 am   #6
Nymrod121
Octode
 
Nymrod121's Avatar
 
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 1,309
Default Re: Co-ax Cable used in DAB Radios.

Aww ... darn it. I have plenty of this type of cable and could have sent you a piece for twice the square root of 'not a lot' (to misquote a certain limerick )

I've done the same thing with a Tevion DAB/FM receiver (ex-Aldi) and a Matsui 'DAB-1' adaptor (Paul Stenning, take a bow ) .

(O.T. swerve here: when used with an external antenna, the Tevion's FM sensitivity and selectivity both seem surprisingly good. I use it as a DX set in the workshop - it's fed from my refurbished Fuba UKA Stereo 8 antenna ... That's it - thanks, mods)

Best wishes
Guy
Nymrod121 is offline  
Old 12th Jul 2018, 9:14 am   #7
Nymrod121
Octode
 
Nymrod121's Avatar
 
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 1,309
Default Re: Co-ax Cable used in DAB Radios.

Quote:
Originally Posted by merlinmaxwell View Post
I thought that DAB radios where 50 ohm.
Domestic receivers tend to be equipped with 75 ohm coaxial connectors (or 300 ohm ribbon sockets/thumbscrew terminals for VHF-FM). Professional test equipment and some lab-grade receivers would be 50 ohm.

Another O.T. alert ...

'In A Previous Life', antenna system impedance vs. receiver input impedance was often a contentious issue arising between a certain broadcasting organisation's Transmitter and Studio Capital Projects departments and their joint Customers in Local Radio stations. LR engineering staff would often query the installation of professional-grade off-air TV/VHF-FM reception antenna systems (whose system impedance was always 50 ohm as standard i.e. Jaybeam et al) being connected to in-building off-air signal distribution systems/receivers which were invariably 'high-end domestic'-grade having a 75 ohm input impedance.

"Oh, the hours we had to spend, before we mastered it in the end" (misquoting Flanders & Swann: 'An Ill Wind')

At this point, Radio Wrangler may well offer his thoughts on how input impedance vs. optimum noise factor can often conspire against the concept of perfect impedance matching re. a receiver input ... over to you, David

Guy
__________________
"No-one's ever complained before!"
"Are they Americans?"
(Joyce Grenfell/Edie Martin: "Genevieve")

Last edited by Nymrod121; 12th Jul 2018 at 9:20 am. Reason: a reflection (non-RF) regarding receiver input impedance vs NF
Nymrod121 is offline  
Old 12th Jul 2018, 10:30 am   #8
mark2collection
Pentode
 
mark2collection's Avatar
 
Join Date: Jul 2010
Location: Royal Berkshire, UK.
Posts: 167
Default Re: Co-ax Cable used in DAB Radios.

RG316 was the stuff I used, in a fairly recent DAB repair.

Looked just like the original too.

Mark
mark2collection is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 8:33 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright ©2002 - 2018, Paul Stenning.