Do tuners go off?

[norriemal]

I recently picked up an Aura tuner with a view to installing a decent antenna once and for all. I have a Denon mid sized stack system in the bedroom which does a good job on radio broadcasts with a T ribbon but when I substituted the Aura tuner it sounded very noisy. I have an old omni directional antenna which I rigged up and things improved a bit but still more noise than I could live with.

My first thought is that it needs a better antenna but I'd hate to sort something out and find that the tuner is less than perfect.

Is there ever any need to service a tuner?

Norrie

 

[Andrew.B]

I've heard they need aligning sometimes, it's a pretty specialised thing you need plastic tip screw drivers for, adjusting the varicaps and stuff inside. Never done it myself, though

 

[sergeauckland]

Yes, tuners do need realigning, and it's not a DIY affair unless one has all the RF test equipment. Older tuners (say before the mid '70s) had tuning capacitors and RF and IF coils that need alignement as time, component ageing and vibration from everyday movements will cause these to drift from their factory settings.

Later tuners were varicap tuned and had ceramic IF filters, so were more robust, and the more modern tuners still (say from mid 80s) were synthesised so more stable still.

However, the RF front-end on all these tuners still have coils and components that require alignment, so it cannot be assumed that after many years they are still in aglignment.

Also, the stereo decoders of older tuners had to be critically aligned, although from the mid 70s onwards, decoders like the MC1310 meant that there was only one pot to adjust. Nevetheless, if the alignment had drifted, then stereo separation and distortion would be worse on weaker signals.

S.

 

[bob atherton]

My Naim 01 needed to be realigned and the power supply recapped. When it came back it sounded quite a bit better but this could have been the P/S I guess.

 

[Mike Reed]

Interesting, as I also have a Naim (unserviced) 01. How does one tell if the head or the p/supply need alignment/a service?

Mine, depite being 20 odd years old, is steady as a rock and sounds divine, yet my (2 x 01 owner) friend thinks I'm silly not to get it done.

 

[norriemal]

Thanks for the info.

With the number of good tuners selling for peanuts just now it's probably not worth the cost and trouble to sort any alignment issues.

I did find a good description of what is required: (about 1/3 way down the page)

http://www.fmtunerinfo.com/index.html#alignments

This also pointed me to a good antenna site:

http://www.kyes.com/antenna/antennadex.html

 

[PsB]

+1 to everything Serge said.
It requires training, practice and specialized equipment.
Some symptoms of a tuner being out of alignment (depending on the technology used) would include a deterioration in the signal/noise ratio, a reduced ability to tune in to weak stations, a reduced ability to separate adjacent stations and asymmetry in the tuning.