SX 1080 tuner reception weak

[I LIKE MUSIC]

A person can loose track of the position of the inductors that are adjusted by using hex alignment tool.

Some tools are marked so that you can tell their position and some are not.

I mark all of by tools by filing a flat area on the handle of the tool (see the picture). That way i can feel the position of the tool and return to the starting point.



The key, especially when staring out, is to go slow. Note the starting point of each adjustment (so it can be returned to the original position), make one adjustment at a time, watch and understand the results. This applies to using off the air signals or a signal generator.

 

[DUALityOFman]

Great tips. Thank you for trying to save me and the 1080 from myself. I will do my best to be gentle. If I make a mess of things, it's certainly in spite of the help I've received here. I'm waiting for tools now.

 

[rcs16]

1. Do not mess with the discriminator adjustments. These are the 2 adjustments in the T6 transformer. You need special test equipment to adjust them and you CAN'T do it without this equipment, and you WILL end up wIth distorted audio and probably no stereo FM.

This needs more explanation, one slug is for center tuning, it has to be centered, the best way is to use a DMM across the meter or appropriate measurement point, usually the AFC and ref bias pins of the quad detector or DC for the ratio detector.
the slug for linearity is where you need a low THD RF SigGen and THD analyzer to get it adj correctly.

ive since acquired a signal generator and while i dont have a distortion meter or a STEREO signal generator to adjust mpx

I have recently aquired a HP 8904A option 001 for my stereo sig gen. , paid around ~$100.00,
for a cheap THD analyzer you can get a HP 333A or use a PC sound card and software.

 

[dr*audio]

This needs more explanation, one slug is for center tuning, it has to be centered, the best way is to use a DMM across the meter or appropriate measurement point, usually the AFC and ref bias pins of the quad detector or DC for the ratio detector.
the slug for linearity is where you need a low THD RF SigGen and THD analyzer to get it adj correctly.


I have recently aquired a HP 8904A option 001 for my stereo sig gen. , paid around ~$100.00,
for a cheap THD analyzer you can get a HP 333A or use a PC sound card and software.

It needs to be centered but without a scope or distortion analyzer you don't know if it's properly tuned in before doing the center adjust. He has no test equipment so he should leave these alone. His problem is a lack of sensitivity. If doing the front end adjustments doesn't fix it, it's component failure and there is no point adjusting for center or distortion.

 

[DUALityOFman]

I don't think it's fair to say I lack sensitivity. I get teary eyed each time I watch It's a Wonderful Life.

 

[dr*audio]

I don't think it's fair to say I lack sensitivity. I get teary eyed each time I watch It's a Wonderful Life.

I knew that was coming...

 

[DUALityOFman]

Yet you went ahead and typed it. What was I to do?

 

[DUALityOFman]

Well, my plastic tools showed up today. "Plastic" and "tools" just doesn't belong together unless you're 2 yrs old, but I'll try. Aren't they prone to stripping out? Now I have to go back over all the helpful instructions from this forum. I'll only try the things least likely to cause me to hate myself later. Stay tuned. Isn't there an emoji sitting at a drum doing a rimshot?

 

[dr*audio]

If you bought the Aven tools they will not strip out. Other ones are softer and will strip or tear.

 

[DUALityOFman]

"Stay tuned"? Hello? I know exactly how Rodney Dangerfield felt.

 

[DUALityOFman]

I'm in it right now and this is what I've learned so far: 1. Plastic tools are REALLY lightweight. 2. T1, T2, and T3 were all pretty good as action flicks go, but I liked the first two best. Seriously...these three adjustments yielded a lot of improvement. I'd say doubled and tripled signal strength, especially with 2 and 3. Now, TC 1,2,3 didn't make much difference, BUT it was clear that when I pressed down on these flathead screws, the signal improved markedly. That probably means something. I'll wait for the responses. They were also incredibly sensitive. The tiniest movement made a big difference. I prefer to avoid those. T5 didn't add much, either. Overall, I'm very happy with the results of a short time and no money invested. Stations seem well-aligned with there positions on the dial, too. The STEREO light used to come on at one or two stations...now it's on 15 or 20 stations.

I'm sure this will mean something to you tuner geeks: (I mean that in a loving way.) the lower/left side of the dial is a good deal stronger than the right/upper side. That may be because most stations are down there? You tell me. Thanks for the help. Now I can tell everyone I used my genius and skills to fix my tuner.

Oh, and I need to replace the bulb for my AUX indicator. I had some small LEDs but too large for this one. If you have a good source, please share. I think the bulb is red, but I'm color blind as hell.

 

[DUALityOFman]

As you were on the bulbs...the bulbs I had only appeared to be too large. It works just fine, and I guess the bulb was not red but a very burned out clear, and it's just the indicator cover that is colored. But you all knew that. All is well.

Is that light green?