i bought this Unit and opened it up because the Tuner was "out of alignment". Being as far from a techie as opne can be the only thig I was able to do was adjust the tuning meter so it co-incided withthe signal strength meter. however a couple of questions:

1. What the heck else does that black box behind the signal and tuning meters do? I saw openings for:

a. Primary - ??
b. Secondary - ??
c. Mutliplex??
d. A 50 v. 75 switch??

I do not want to play with them If I do not knwo what they do.

2. Is there an "easy way" to move the sdignal indicator sp that it aligns with the actual station e.g. 104.5 now reads closer to 104.9. I think I wouild have to opemn the metal holding the tuning string but it looks lijke with the wrong move I could break the indciator.

3. I think I have seen another post for this one, - the FM tuning lights at either end of the dial are out for the most part. How can I change them to check them?

4. Does anyone have a free operating/service manual they can email as I have done for others? I am not sure I will be keeping the uinit.

Darrell in Toronto

I dunno about the 881 in particular but I have realigned the tuning string assembly in a few different $5 goodwill receivers. Sometimes I got lazy and held the tuning cap (though not by vital parts!) when I reached a desired frequency then aligned the pointer, or if allowed moved the pointer along. The 50-75 is probably the deemphisis switch, on my Olson RA-250 this is actually an external switch. Multiplex is best akin to what causes the ghosting effect on TV signals picked up via an antenna, extra signal reflections picked up off buildings and stuff. Some receivers have meters for giving an indication of how the multiplex is. On my Fisher RS-1080 for instance you center the channel, find its best signal strength and try and get the mulipath meter to drop down all the way to the left for the best result. As I say I have not particularly worked on an 881 but thats my take on at least two of the fuctions, without a service manual its just a guess.

Thanks for the info.

What does the "de-emphasis" switch do?


Darrell

Multiplex is FM stereo. You're thinking of multipath. :)

In any case, if the tuner is out of alignment it needs to be aligned by a technician skilled in tuner alignments....this is not a beginner's job.

TP

"Alignment" seems to be getting used in two different senses in this thread.

If the tuner is able to tune in stations normally, but it just reads at the wrong place on the dial, it is usually possible to loosen the tuning string or the wheel that it goes around to alter the setting of the tuning capacitor (the thing with all the moving fins) in order to adjust where the dial pointer is. Think of this as "dial pointer alignment"; when changing this, none of the electronics are actually changed. I've done this a number of times. It's a little difficult on my Sansui Eight, which uses two separate tuning capacitors, one for AM and one for FM.

A tuner alignment checks and fixes the parts involved in tuning in stations. Setting the dial pointer would be part of this process. Take a look at this page about Dynaco FM-5 alignment (http://home.indy.net/~gregdunn/dynaco/components/FM5/align.html) .

Not thinking straight earlier, must have had one too many beers while working on the pool. Ah well, yep, multipath is what I was talking about, multiplex is stereo.

Thanks.

Why would you an adjustment screw for "multipath"? Either a signal is stereo or mono correct? Can you make something "more stereo or less stereo" by turning it?

Darrell