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Pioneer SX690 Tuner Amp

I have owned this tuner/amp for some 35 years and it has never let me down, other than it crackling when adjusting the volume for the first minute or so.
Question, there are two types of external aerial connections at the back of the unit. One is marked "300 ohm unbalanced" and the other is marked "75 ohm balanced".
I intend to install a half wave dipole external aerial to improve my FM reception, and have been advised by the aerial supplier to use the 75 ohm connection. What is the connection - is that a DIN plug connector in the back of the amp?
Any help gratefully received.
Thanks



Re: Pioneer SX690 Tuner Amp

Its a crazy thing that older Pioneer used a wrong chassis connector for 75 Ohm coax cable. It was a tv chassis female connector ! Later theyre used a male chassis connector. SX- 690 has a female chassis connector.

karodimitrov's picture

Re: Pioneer SX690 Tuner Amp

Yours is more modern - my Technics is with knobs.:)))

karodimitrov's picture

Re: Pioneer SX690 Tuner Amp

With a 75 ohm connection you can use 75 ohm coax for the lead in. With a 300 ohm connection you have to use 300 ohm twin lead cable for the lead in.75 ohm coax can be routed anywhere. Parallel transmission line has the advantage that its losses are an order of magnitude smaller than coaxial cable. Its disadvantages are that it is more vulnerable to interference, and must be kept away from metal objects which can cause power losses.Half wave is good idea.Connector is the same as on TV. "FM 75 Ohm UNBAL"

Re: Pioneer SX690 Tuner Amp

Hi Karodimitrov,
Excellent - thank you! You are absolutely right. See my other reply to you - have discovered that my Pioneer has a simple coax female terminal for the 75 ohm connect. Out of the 2 connectors, (330 v 75 ohm) I will go with the 75ohm connect.

Thanks for your very kind advice.

Mike

karodimitrov's picture

Re: Pioneer SX690 Tuner Amp

It was a pleasure.