Beomaster 5000 Tuner - 75 Ohm Coaxial Connection

I have a newly aquired 1967 BM5000 tuner. I have a 75 Ohm coaxial aerial socket (fed from my roof antenna) that I need to connect to the BM5000. The BM 5000 has both 300 Ohm and a 75 Ohm flat cable connection sockets. What do you think would be the best way to make the conversion/connection?

My guess is, that it will work fine either way but if your antenna is a 75 Ohm type, I would prefer to use that socket.

Martin

Dillen:

My guess is, that it will work fine either way but if your antenna is a 75 Ohm type, I would prefer to use that socket.

Yes, definately use the 75ohm connection, but I'm guessing Bristol's question was more about how to physically attach the 'coax' wall outlet to the 'flat' 75ohm aerial connection on the Beomaster.

 

You ideally want to connect the outer screen of the coax to the terminal connected to GND (the one on the right in the above image) and the centre core to the terminal on the left which is the input to the tuner. I'm not sure though whether there is any indication on the Beomaster as to which is which or whether the connector itself is keyed in any way?

Kind Regards,

Martin.

If your after a plug that fits I have a bag of them somewhere.

Lee

Thank you Gentlemen for the rapid replies. My question was concerning the physical and electrical connection. My roof antenna is connected via 75 ohm coaxial cable around the house. I think the 75 ohm input does make most sense.

I am concerned about how much signal would be lost/reflected if I just split the braid and core of a coaxial cable to feed the flat cable input on the BM5000. Is there a better way? Perhaps I am worrying too much, but I was thinking the best signal into the tuner will produce the best sound out.

Bristol603:

I am concerned about how much signal would be lost/reflected if I just split the braid and core of a coaxial cable to feed the flat cable input on the BM5000. Is there a better way?

It'll be fine to do this. But if you're concerned then try to keep the unshielded section of cable as short as possible by making the join between coax and unshielded cable as close to the rear of the BM as you can.

Bristol603:

Perhaps I am worrying too much, but I was thinking the best signal into the tuner will produce the best sound out.

Broadly speaking yes, but many of these tuners operated quite happily with ribbon style antennas so I very much doubt signal strength will be an issue with a roof mounted FM antenna. Indeed, according to the manual, the third socket is a 75ohm input with attenuation for when you are close to local transmitters and the signal level is too high.

Kind Regards,

Martin.

I am in precisely the same position also having a newly acquired p.m. 5000

 

Despite all the helpful information given by other responders, were are you in fact hoping  that someone would come up with an idea for a short cable that would go from your FM socket in the wall to a plug suitable for the back of the BM 5000? 

What did you actually do in the end and is it working well?

Alan 

 PS do you actually drive the eponymous motor? 

I would make an adapter, something like this on the picture but of course not with T-type but with flat cable connection socket at the Beomaster side.

Regards,

Theomaster

Hi Alan,

I followed the suggestion in the replies and connected via a short unscreened section to the 75Ohm input. It works fine. I believe any signal degradation at the UHF input has minimal impact compared to other factors, e.g. speaker selection/placement and/or age related hearing loss. A nice tidy adaptor/cable would be great, but I didn’t find one.

Regards,

Nigel.

Yes - the 603 is tucked up in the garage at present as it isn’t the best on slippery roads - it does about 5000 miles pa during the summer months.

Almost anything will work with this superb tuner. It will pull radios with nothing connected to it as a matter of fact, for heaven’s sake

I use the 75 ohm aerial input with a dipole aluminium aerial. I made an adapter for that.

Hiss is very low and on a par with only my Beomaster 8000 (the best on every account).