CD Player Interferes With Radio Reception ?

When my CD player (Philips CD630) is switched on and connected to my amp
(NAD C350), there is interference on the radio reception (Denon 260 - the
interconnect runs close to the wire dipole antenna). If I switch off the
player it disappears; If I disconnect the CD-amp interconnect but leave the
player switched on, it also disappears. Would I be correct in assuming that
the problem is due to inadequate screening in the interconnect?

If so, can you recommend any suitably well screened, inexpensive,
alternatives to the bog standard interconnects (as typically supplied with
equipment) which I am currently using - I am totally happy with the
'performance' of these cables, so the only reason for changing is to solve
this problem (I'm not into all the rubbish, IMHO, talked about the
subjective performance of cabling).

TIA.

"tony sayer" wrote in message
...
In article , Cal
writes
When my CD player (Philips CD630) is switched on and connected to my amp
(NAD C350), there is interference on the radio reception

SNIP




If I were you I'd give the tuner a better signal to play with rather
than try to fix this with better shielded cables. Try a simple dipole
aerial a little distance away from your tuner and run a co-ax cable to
your tuner.

Apart from that it does seem strange that your tuner is radiating
frequencies up into the FM band. It *is* the FM band you have this on
isn't it?, not medium wave..
--
Tony Sayer


Yes, FM.

BTW, please excuse my ignorance, but do you mean CD player radiating?

I have thought about putting up an external antenna, but I get noise free
stereo reception with the wire dipole, so I wasn't sure if it was worth
it???

Also, I have some CT100 left over from my TV antenna installation - is this
suitable for use with FM antennas too?

TIA.

In article , Cal
wrote:

"tony sayer" wrote in message
...


Apart from that it does seem strange that your tuner is radiating
frequencies up into the FM band. It *is* the FM band you have this on
isn't it?, not medium wave.. -- Tony Sayer

The Meridian 263 radiates quite a lot of RF. This can certainly be picked
up by something like a CT7000 if the antenna is only a few metres fro the
263 and its cables. Given the good performance of the CT7000 I suspect that
RF at the desired VHF frequencies is the cause.

I suspect it is clock harmonics, etc, that may extend up to band II. In
terms of digital signals the levels may be small, but might be large enough
to cause problems is radiated near to the antenna.

It may also be worth bearing in mind that the interference may be radiated
via the mains leads or cable screens.

Ideally, the best solution is good VHF cable and an antenna well away from
the CD player. However a secondary method might be to use ferrite blocks or
rings on the mains and signal leads of the CD player.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

On Sat, 26 Jul 2003 22:31:19 +0100, "Cal" wrote:

When my CD player (Philips CD630) is switched on and connected to my amp
(NAD C350), there is interference on the radio reception (Denon 260 - the
interconnect runs close to the wire dipole antenna). If I switch off the
player it disappears; If I disconnect the CD-amp interconnect but leave the
player switched on, it also disappears. Would I be correct in assuming that
the problem is due to inadequate screening in the interconnect?

No, the problem is your use of a totally inadequate antenna......

If so, can you recommend any suitably well screened, inexpensive,
alternatives to the bog standard interconnects (as typically supplied with
equipment) which I am currently using - I am totally happy with the
'performance' of these cables, so the only reason for changing is to solve
this problem (I'm not into all the rubbish, IMHO, talked about the
subjective performance of cabling).

Any heavily shielded cable such as URM 70 will do the job, but you may
also need to look at the quality of earth connection to your system.
As noted, however, the real solution is to improve your antenna
arrangement, which will also greatly improve your FM reception.

Alernatively, just switch off the CD player when you're listening to
the radio! Duh.......
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Sat, 26 Jul 2003 23:16:18 +0100, "Cal" wrote:


"tony sayer" wrote in message
...
In article , Cal
writes
When my CD player (Philips CD630) is switched on and connected to my amp
(NAD C350), there is interference on the radio reception

SNIP

If I were you I'd give the tuner a better signal to play with rather
than try to fix this with better shielded cables. Try a simple dipole
aerial a little distance away from your tuner and run a co-ax cable to
your tuner.

Apart from that it does seem strange that your tuner is radiating
frequencies up into the FM band. It *is* the FM band you have this on
isn't it?, not medium wave..
--
Tony Sayer


Yes, FM.

BTW, please excuse my ignorance, but do you mean CD player radiating?

Yes, he does, and the player should not be radiating in any band
picked up by the tuner. However, your placement of the interconnect
alongside the aerial means that a receiver designed to work with
microvolt signals is being subjected to many millivolts of interfering
signal, which may be (indeed clearly *is*) enough to swamp the
sensitive input circuits.

I have thought about putting up an external antenna, but I get noise free
stereo reception with the wire dipole, so I wasn't sure if it was worth
it???

You'll pull in more stations with a better antenna, and reduce the
effects of other potential intereference sources.

Also, I have some CT100 left over from my TV antenna installation - is this
suitable for use with FM antennas too?

Yes.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

"Stewart Pinkerton" wrote in message
...
On Sat, 26 Jul 2003 22:31:19 +0100, "Cal" wrote:

When my CD player (Philips CD630) is switched on and connected to my amp
(NAD C350), there is interference on the radio reception (Denon 260 - the
interconnect runs close to the wire dipole antenna). If I switch off the
player it disappears; If I disconnect the CD-amp interconnect but leave
the
player switched on, it also disappears. Would I be correct in assuming
that
the problem is due to inadequate screening in the interconnect?


snip

Alernatively, just switch off the CD player when you're listening to
the radio! Duh.......


:-)

snip
When my CD player (Philips CD630) is switched on and connected to my amp
(NAD C350), there is interference on the radio reception (Denon 260 - the
interconnect runs close to the wire dipole antenna). If I switch off the
player it disappears; If I disconnect the CD-amp interconnect but leave
the
player switched on, it also disappears. Would I be correct in assuming
that
the problem is due to inadequate screening in the interconnect?


If I was you I'd invest in a nice 3 or 4 element roof or loft aerial. Not
just to eliminate the tuner interference but given tuners work much better
with a stronger signal (those simple indoor dipole wires dont give as much
strength as you may imagine) your tuner will love you for it.

Steve

In article , Cal
writes

"tony sayer" wrote in message
...
In article , Cal
writes
When my CD player (Philips CD630) is switched on and connected to my amp
(NAD C350), there is interference on the radio reception

SNIP




If I were you I'd give the tuner a better signal to play with rather
than try to fix this with better shielded cables. Try a simple dipole
aerial a little distance away from your tuner and run a co-ax cable to
your tuner.

Apart from that it does seem strange that your tuner is radiating
frequencies up into the FM band. It *is* the FM band you have this on
isn't it?, not medium wave..
--
Tony Sayer


Yes, FM.

BTW, please excuse my ignorance, but do you mean CD player radiating?

Yes. Thought I've never seen or heard of this before. Seems it might
have a fault with it possibly. Though I don't have Radio tuners fed by
owt else than good aerial systems:-))..

I have thought about putting up an external antenna, but I get noise free
stereo reception with the wire dipole, so I wasn't sure if it was worth
it???

Well I live in a good signal area, but still have the correct outside
aerial/s for the best reception. Especially this time of year with the
Proms. I consider that money very well spent!..

Also, I have some CT100 left over from my TV antenna installation - is this
suitable for use with FM antennas too?

CT100 is an excellent cable for SAT/TV/FM and is far better than the
"damp string" that is usually sold as low-loss aerial cable. If you're
looking for FM aerials via mail order www.cpc.co.uk or .com is one of
the better suppliers. They do a fairly good range. What ever you do
avoid those horrible Circular things go for a multi-element array and
point this at the transmitter.

Good listening..

TIA.



--
Tony Sayer

Bancom Communications Ltd U.K. Tel+44 1223 566577 Fax+44 1223 566588

P.O. Box 280, Cambridge, England, CB2 2DY E-Mail

TL447-553 52* 10.57'N 0* 6.96 E

In article , Cal
writes

"Laurence Payne" wrote in message
.. .
When my CD player (Philips CD630) is switched on and connected to my amp
(NAD C350), there is interference on the radio reception

.

If for some strange reason you MUST have the CD powered up while
listening to radio, get a better aerial or re-locate the cables.

As mentioned in reply to SP, when listening to CD while recording radio. And
before anyone asks, it's so I can timeshift and listen with the option of
fast forwarding through all the inane presenters, ads, tracks I don't like
etc.

Guess it's time to install an external antenna - Any recommendations? 3
element from Antiference or Triax?


Both of these makes are good. The one I'd avoid is the Maxview sold by
Maplins as they, IMHO ,leave quite a bit to be desired especially with
the balun transformer to match to the cable.

The last one I saw didn't even have one. Not the done thing to have a
balanced source connected to an unbalanced feeder..

--
Tony Sayer

On Sun, 27 Jul 2003 12:23:47 +0100, "Cal" wrote:

"Laurence Payne" wrote in message
.. .
When my CD player (Philips CD630) is switched on and connected to my amp
(NAD C350), there is interference on the radio reception

If for some strange reason you MUST have the CD powered up while
listening to radio, get a better aerial or re-locate the cables.

As mentioned in reply to SP, when listening to CD while recording radio. And
before anyone asks, it's so I can timeshift and listen with the option of
fast forwarding through all the inane presenters, ads, tracks I don't like
etc.

Guess it's time to install an external antenna - Any recommendations? 3
element from Antiference or Triax?

Most folks would recommend Antiference, but basically *anything* will
be a vast improvement. My kitchen system (also on a Denon TU-260L, as
it happens), has a coax lead going up some nine feet to a simple wire
dipole nailed to a ceiling beam in the hallway. Reception is
excellent, and no problems with interference from other bits of kit.
--

Stewart Pinkerton | Music is Art - Audio is Engineering