hello from an oldude from the woods (near KC MO)

[oldude2]

hello, I recently bought this panasonic RE-8420 at a thrift store for the whopping sum of $24.99, so far View attachment 76951View attachment 76951 I've connected my turntable & have been having flashbacks to my youth as I dig into my much neglected vinyl stack, I have very little technical knowledge, so I may have some nEwB questions as time goes by

 

[Sonik Wiz]

hello, I recently bought this panasonic RE-8420 at a thrift store for the whopping sum of $24.99, so farView attachment 76950View attachment 76951View attachment 76951 I've connected my turntable & have been having flashbacks to my youth as I dig into my much neglected vinyl stack, I have very little technical knowledge, so I may have some nEwB questions as time goes by

Pleased to meet you! Nice pics & nice intro. I am also near KC MO, The burbs of JOCO. There are a few others around from the general area. Looking forward to hearing more from you!

 

[oldude2]

thanks, I live in the poor johnson county (missouri near warrensburg)

 

[Sonik Wiz]

thanks, I live in the poor johnson county (missouri near warrensburg)

Well, I live in the poor part of JOCO KS, North East. Now where you live I imagine you get some great ATMOS fly over effects from Whiteman!

 

[oldude2]

Well, I live in the poor part of JOCO KS, North East. Now where you live I imagine you get some great ATOMS fly over effects from Whiteman!

looking up

 

[kap'n krunch]

hello, I recently bought this panasonic RE-8420 at a thrift store for the whopping sum of $24.99, so farView attachment 76950View attachment 76951View attachment 76951 I've connected my turntable & have been having flashbacks to my youth as I dig into my much neglected vinyl stack, I have very little technical knowledge, so I may have some nEwB questions as time goes by

Hello oldude!
this was the receiver which introduced me to quad in 1975, my stepfather bought this and a lot of Ray Conniff Q8s...
IIRC, this has no decoder for TTs so the only Quad you could play would be Q8s which are expensive and very difficult to restore (opening, splicing the tape, etc. unless you are good at it or feel like learning ).
At this point in time the Q8 player will probably need a lot of TLC; belt and roller replacement and the amp would need recapping but it's still a nice piece of memorabilia..the amp was pretty decent and the speakers that used to come with it were very good for being full range and they were connected via rca plugs...

Welcome to the Forum and be prepared to invest in some gear, although a minimal setup with an HDMI to RCA converter (cheap) with a bluray player (still cheap) and some powered monitors (not that cheap but worth it) will be a treat!

 

[oldude2]

haven't tried the Q8, not interested in learning to splice tape

 

[MidiMagic]

Don't the Panasonic units have a Quadruplex decoder? It was a generic RM decoder.

 

[oldude2]

I haven't a clue ?

 

[oldude2]

but now iI'm curious

 

[Sonik Wiz]

but now iI'm curious

The switch laeled AFC stands for Auto Field Composer, IIRC. There is surprisingly scant detailed info of this feature on the web, pr even that receiver model. But the AFC was indeed a cheap and cheerful way to synthesize quad from a 2ch source. Very easy to check out. Just hook up your 4 speakers, play something stereo like FM radio and listen for action in the rear speakers. Bonus tip: if the radio is playing an DJ or commercial, this may be effectively mono & you shouldn't hear hardly anything out of the rear. Wait for real music.

The QPLEX function was a scheme to hook up an outboard quadraphonic FM demodulator which never came about.

The 4ch AUX is a way to hook up an external decoder such as CD-4 or real quad decoder.

The Panasonic RE-8420 has been mentioned here there before on the forum. Give it a search & you might find something useful.

 

[oldude2]

The switch laeled AFC stands for Auto Field Composer, IIRC. There is surprisingly scant detailed info of this feature on the web, pr even that receiver model. But the AFC was indeed a cheap and cheerful way to synthesize quad from a 2ch source. Very easy to check out. Just hook up your 4 speakers, play something stereo like FM radio and listen for action in the rear speakers. Bonus tip: if the radio is playing an DJ or commercial, this may be effectively mono & you shouldn't hear hardly anything out of the rear. Wait for real music.

The QPLEX function was a scheme to hook up an outboard quadraphonic FM demodulator which never came about.

The 4ch AUX is a way to hook up an external decoder such as CD-4 or real quad decoder.

The Panasonic RE-8420 has been mentioned here there before on the forum. Give it a search & you might find something useful.

 

[oldude2]

thanks Sonic Wiz, very useful info, I learned a bit just now darn it I have 4 speakers connected & have flipped all switches & turned all knobs, & trial & error, still have scratchy sliders & such, going to get a new can of de OX it when I can

 

[Soundfield]

The switch laeled AFC stands for Auto Field Composer, IIRC. There is surprisingly scant detailed info of this feature on the web, pr even that receiver model. But the AFC was indeed a cheap and cheerful way to synthesize quad from a 2ch source. Very easy to check out. Just hook up your 4 speakers, play something stereo like FM radio and listen for action in the rear speakers. Bonus tip: if the radio is playing an DJ or commercial, this may be effectively mono & you shouldn't hear hardly anything out of the rear. Wait for real music.

Wasn't Panasonic's universal decoder called Acoustic Field Dimension (AFD)? Panasonic units with such a circuit had associated 'width' and 'depth' controls which this unit doesn't. I'd have thought the AFC switch was actually just the common or garden FM tuning AFC. I think it may be the Q'Plex switch that engages some more basic quad synthesis (hafleresque style).

 

[Sonik Wiz]

Wasn't Panasonic's universal decoder called Acoustic Field Dimension (AFD)? Panasonic units with such a circuit had associated 'width' and 'depth' controls which this unit doesn't. I'd have thought the AFC switch was actually just the common or garden FM tuning AFC. I think it may be the Q'Plex switch than engages some more basic quad synthesis (hafleresque style).

Yeah you could be right. I thought AFC circuits were phased out by the 70's in favor of frequency synthesis. As I said not much info on this unit unless you want to spend some $$ & buy a service manual.

I look forward to OD2 sharing what he finds out about this as time goes on.

 

[Soundfield]

Yeah you could be right. I thought AFC circuits were phased out by the 70's in favor of frequency synthesis. As I said not much info on this unit unless you want to spend some $$ & buy a service manual.
I look forward to OG2 sharing what he finds out about this as time goes on.

Yes, you're right, varicap PLL tuning largely did away with the AFC switch, but I'm thinking that this wasn't a particularly high end unit and probably had a pretty basic front end. As you say though, difficult to find much info on this one (nothing on HifiEngine and a clip on YouTube of a bloke more or less just randomly fiddling with the controls of one!). Maybe OD2 can find out how it works!

 

[oldude2]

Wasn't Panasonic's universal decoder called Acoustic Field Dimension (AFD)? Panasonic units with such a circuit had associated 'width' and 'depth' controls which this unit doesn't. I'd have thought the AFC switch was actually just the common or garden FM tuning AFC. I think it may be the Q'Plex switch than engages some more basic quad synthesis (hafleresque style).

from my trial & error, with the selector switch on "fm stereo" & in "Q plex" mode, I get sound from all 4 speakers, moving from "Q plex" mode to stereo mode, seems to cut out the rear speakers, moving the selector to "fm" brings back the rears, so all 4 are playing, with the selector in "fm" the Q plex/stereo switch has little to no effect,
I tend to think the AFC is related to tuning, on a strong station it has little to no effect on a weak station, "AFC on" brings a bit better reception.

 

[oldude2]

Yes, you're right, varicap PLL tuning largely did away with the AFC switch, but I'm thinking that this wasn't a particularly high end unit and probably had a pretty basic front end. As you say though, difficult to find much info on this one (nothing on HifiEngine and a clip on YouTube of a bloke more or less just randomly fiddling with the controls of one!). Maybe OD2 can find out how it works!

I saw that you tube, if it's the same one his 8 track was Englebert Hunperdinck's greatest hits, is it bad that I remember those hits from their original airplay on top 40 am radio

 

[Soundfield]

from my trial & error, with the selector switch on "fm stereo" & in "Q plex" mode, I get sound from all 4 speakers, moving from "Q plex" mode to stereo mode, seems to cut out the rear speakers, moving the selector to "fm" brings back the rears, so all 4 are playing, with the selector in "fm" the Q plex/stereo switch has little to no effect,
I tend to think the AFC is related to tuning, on a strong station it has little to no effect on a weak station, "AFC on" brings a bit better reception.

I think this is pretty much what I’d expect if my interpretation of the switches was correct.

With the mode selector set to FM Stereo, and the QPlex/Stereo switch set to Qplex it synthesises a quad signal for the rear channels. When you put the Qplex/Stereo switch to the Stereo position it just sends a normal stereo signal to the front speakers only and the rear speakers are disconnected. When you put the mode selector to FM you are forcing it into mono and so there is no way to synthesise a quad signal. In this situation the Qplex/Stereo switch has no effect and mono is sent to all four speakers.

You seem to be confirming that the AFC switch is indeed Automatic Frequency Control for the FM tuner.

Hope you can get the noisy controls cleaned up!

 

[kfbkfb]

Panasonic/Technics Acoustic Field Dimension system description


Kirk Bayne