Technics ST-8080 very weak reception

jdsalinger

AK Subscriber
Subscriber
Hi guys,
I'm not really familiar with tuners, but this year I've acquired 3 and have discovered how nice FM can really be using a tuner.

Problem is that my listening room is in the basement of our house. I have an ST-8080 that sounds great and has good reception upstairs (ground level) using a basic T-ribbon antenna, but gets next to nothing in the basement.

I recently tested a Yamaha CT-610ii and Scott 530T in the basement, same spot, same antenna and they have great reception down there.

Any suggestions as to what might be causing the weak reception? I'm capable of DIY, but don't have a signal generator, O-scope or other gear.
 
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I'm not trying to be lazy by the way. If this is a matter of a better antenna, I will research the many threads on reception in the Tuners forum.
I just assume something is wrong with the ST itself, since two other tuners with lower sensitivity (than the ST) were able to receive plenty of stations when the ST only picked up 1 or 2.

I'm just not familiar with how tuners work and where to investigate. I assume the tuner is aligned well enough because it pulls in stations just fine on the first floor of the house.
 
find and download the service manual, follow the tips (but not the tuning steps).

the technics of that era were SOTA - SP10s, the 9038 tuners, RS9900s, etc
 
your issue is all antenna location/direction related, you need to have your antenna as high as possible (best) or close to a window with access to the direction the signal is coming from.
 
Thank you, but why then do the other two tuners with similar or exact same sensitivity work well, while the ST doesn't?
Same location, same antenna same direction.

That doesn't make sense to me.
 
Okay I misunderstood what you wrote, I guess that the ST-8080 might need an alignment check. I looked over the schematic, it should have good sensitivity based on the 2 stage jfet RF front end design. There are a number of components in the RF signal path which could cause less sensitivity if they are going faulty or out of adjustment. No easy way to point to one particular place to look.
 
This is a copy and paste I left in a different thread that was similar to this.:
You can tune them in pretty well just by sweeping the adjustments. It helps if you have a service manual, but not even necessary. Try sweeping each trimmer-cap and tuner coil starting at the lowest numbered adjustment on the board. They usually start at '1'. This will be starting at the antenna and front end and working inwards. While sweeping each adjustment back and forth, watch the signal meter and center it on the highest level. It helps to have a manual to know what points are AM and what is FM, but it can be done by process of elimination by making notes what each does. Some adjustments will have a "hard" edge one way and a "soft" edge the other. It will fade slowly in one direction(soft edge) and get clear right before it turns to distortion(hard edge) the other direction. You want to get it in the clear amplified stage before the distortion. If you have a good ear you can get some of these pretty much right on. Just repeat the procedure as many times as necessary to make sure one stage didn't negatively effect the ones you just tuned before it.
This should at least tell you if it just needs an alignment. If something is broke, you will need the proper equipment to diagnose and properly align it. I have had tuners go from receiving no stations at all, to the best reception of any tuner I have tried by doing this. I would focus mostly on the trimmer caps and coils though. The potentiometers on the board can be for filters and stereo separation, which may be hard to hear and set right. Also a couple pots. usually for the AM and FM meter levels adjustment as well.
 
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