GOING HIFI

[posting this a day later than I wrote it]

I got all distracted telling you about how distracted I was getting 
yesterday, so never got onto my designated weekend job of fixing 
the guttering on part of the shed. Now though the fog from last 
night is still out and the temperature outside seems even lower, 
still, at 10AM. Somehow being fully clothed up a ladder trying to 
screw in cold metal parts works worse in winter than running around 
naked for me, indeed cold hands are getting to me a little even 
typing this. My 4G mobile internet connection has given up in the 
fog too (for the second day in a row, shame I ran into problems 
with my outdoor antenna plan so that still isn't finished either). 
So I'll write up another one of my phlog post ideas...

I've ranted here somewhere before that I don't really buy into the 
pursuit of quality for media consumption. All the fuss over high 
resolutions and lossless compression and HiFi. Sure you get a 
slightly improved experience for 10x or 100x the price of the 
cheapest option, but it's really barely relevent to the experience 
of finding something new that you really enjoy. I think time and 
money are better spent on finding new content rather than trying to 
pull something extra out of an experience you already know.

That being said, my mother recently gave me an old 1980s boombox, 
given to her by a friend, who'd been given it by a friend. In spite 
of this chain of people wanting to get rid of it, it's actually by 
far the best boombox I've ever got my hands on (and I've picked up 
a good few at garage sales over the years). It's a Sony FH-7 Mk II, 
which unlike my other boomboxes and mono cassette-radios is so nice 
people have actually bothered to write about it (a little bit) on 
the Web. There's even, shockingly, a PDF of the service manual 
available for download, which I soon took advantage of. 
Nevertheless as a traditional boombox that a 1980s teenager would 
mount on his shoulder to annoy the neighbours, this thing's 15Kg 
weight would make that something of a athletic event. That weight 
isn't even after loading it up with the typical national stockpile 
of D-cell batteries, because it doesn't actually have a battery 
compartment - mains only. It's really a miniaturised version of a 
"component" sound system, with separate modules for each function, 
stacked up and bolted together with some detachable speakers, then 
with a detachable handle thrown on to make it "portable". But in 
return you got the quality of a component sound system, and a silly 
price tag to match.

Actually they even seem to be genuinely worth something today too. 
I'm not sure about the sanity of Ebay sellers asking thousands for 
one, but the sold listing show that $600AUD seems achieveable for a 
working example. So I was very tempted to sell it, but I've been 
using some cheap PC speakers for my TV since its built-in mono 
speakers died, and although they're alright most of the time some 
frequencies cause a reverberation in their plastic enclosures and 
corresponding buzzing sound which gets annoying when someone's 
voice or a recurring sound effect triggers it. This thing is 
definitely at the other end of the spectrum for second-hand audio 
gear, and after hooking the Aux. input up and wobbling some life 
out of the long-untouched volume control, I had to admit that, in 
spite of what I've said about HiFi being pointless, yeah it did 
sound _really_ good.

So combine that with the fact that, as a pretty perfect 
manifestation of 1980s trendy tech, its value will probably 
continue to increase in the collector's market over the years, I 
figured I might as well take the opportunity to put it to use 
myself.

Since I keep a cheapo 80s boombox near the TV already for playing 
radio and cassettes, it ought to replace that. But upon first test 
the FH-7's fancy auto-reverse-playback cassette player/recorder 
would just continuously clunk between forward and reverse playback 
modes. So first I decided I had to fix that, and clean up the dirty 
volume (etc.) slide potentiometers on the amplifier too. One of my 
couch-based repair jobs since it's too cold to be away from the 
heater in the lounge room during the evenings at this time of year 
(and I'm starting to think in the daytime too, today).

The volume pot was fairly easy. It's a bit recessed so you have to 
take the case off but then you can squirt some contact cleaner in 
and after working it back and forth for a while it's now back like 
new. The tape player was more of a pain since with all the fancy 
solenoids and four circuit boards of electronics it's all a bit 
more crammed-in than the cheap, mechanically controlled, tape 
mechanisms I'm used to. It also has lots of belts - five of them, 
which mostly seemed to be turning OK and that got me quite 
confused, but it turned out the belts on the motor were slipping 
alternately - one slipped in forwards playback mode and the other 
slipped in rewind, and although at first I thought this was some 
clever clutch mechanism at work, a bit more light revealed it was 
just cracked old belts slipping under load.

I have a small stockpile of tape belts from the era, even some 
official Sony replacement parts, but none to match. Ebay sellers 
offer complete belt sets, but for around $60AUD! Hunting through 
the parts manual found part numbers for four of the belts (it seems 
to deny the existance of one belt - a design change perhaps?), and 
ignoring the two tape counter belts which seemed to still be 
working (and also hard to access), I managed to find these specs 
online:

Sony 3-530-181-XX BELT, COUNTER
Sony 3-533-636-00 BELT (A), COUNTER

Sony 3-307-366-00 BELT, FAST FORWARDS (qty. 2?)
Inside Circumference: ~4.6Inch / 11.7cm
Thickness: ~0.046 (3/64th)"/ 1.2mm
Shape: Square

Sony 3-307-483-00 BELT (R), CAPSTAN
Inside Circumference: ~8.6Inch / 21.8cm
Thickness: ~0.025"/ 0.6mm
Width: ~0.125 (1/8th)"/ 3.2mm
Shape: Flat

After a fair bit of searching, I found a close-enough match for the 
capstan belt, and an assortment of small belts in the right range 
for the fast-forwards and unidentified belts, on Aliexpress. Total 
cost about $10AUD, including all the extra charges that Aliexpress 
springs on you at the last moment these days.

When they arrived a couple of weeks later I managed to fit them in, 
lubricated a stiff pinch roller, and put it back together... to 
watch it eat my test tape. Well it's not so bad, since it seems to 
play safely and reliably in forwards playback mode, and 
rewind/fast-forwards mode, but the take-up spool seems to 
intermittently stop turning after a while in reverse playback mode. 
Maybe that's from the grease I accidentally got on the capstan belt 
while trying to awkwardly hook it on and couldn't wipe off very 
convincingly? Or maybe the belt size/material just wasn't close 
enough? Or maybe I knocked something else out of alignment whle 
poking around inside? The exploded diagram in the service manual 
showing hundreds of tiny gears, levers, and solenoids flying out at 
you is terrifying, so I decided to leave it at that and just swich 
off continuous play mode. So I'll flip the tape over manually at 
the end of each side like I always have done. That's one advantage 
of only needing to fix things up for my own use as opposed to 
selling them on Ebay as fully working.

Of course I couldn't resist popping the lids of the other 
"components" of the sound system to see what's inside them too. 
Electronic component date codes all looked to be for 1985, so I 
guess it was made around then. Particularly interesting was the 
power supply, where the bulk of the weight seems to be, courtesy of 
a nice brick of a low-profile mains transformer. It's good to see 
it has a real mains power switch in there too, so it's not pulling 
standby power all the time while seemingly turned off, like so much 
modern tech does. I have unplugged power the radio section for now 
though (connected externally by ribbon cables at the back) since I 
haven't worked out how to connect an aerial to it yet, and ABC 
Classic which I normally listen to is also broadcast via Digital TV 
so I can get it from the set-top box anyway.

Also, as one of the early digitally-tuned analogue radios (with an 
LCD display in the mid 1980s, no less!), I'd say the user interface 
is in dire need of refinement. It doesn't have any channel scan 
mode, nor any way to store channels, so you have to scroll the 
frequency to your desired number with the +/- buttons (while 
holding FAST for a somewhat quicker journey) each time you want to 
change channel. I always prefer the feel of tuning in a station 
with an analogue control anyway, but this digital design seems 
particularly painful. Still, it does tune to the shortwave bands as 
well as regular AM/FM (a feature that actually seems to have been 
lost in the follow-up models), so even though I'm sure I'd always 
prefer twiddling the big knob on an ananlogue SW receiver, it might 
be fun one day to hook up an aerial to it and try out tuning to 
exact known frequencies instead of just twiddling around somewhere 
in the airwaves +/-1MHz.

Speaking of digital, it confused me that the Aux. input on the 
front is labeled "CD/Aux." (phono input is at the back, and Sony 
actually made a cool little direct-drive record player in the same 
footprint that fits on top). I've always had CDs in mind as a late 
1980s technology that I saw take over from cassettes in the 
mainstream while I was growing up in the late 90s and early 2000s. 
But a look on Wikipedia reveals that CDs came out right at the 
start of the 1980s, had albums selling over a million copies by the 
mid 1980s, and Sony had their second model CD player on sale by the 
time the FH-7 was made (they didn't have one in its 
"mini-component" format for a few more years though). It just shows 
how much slower new technology used to roll out, especially to the 
then slightly backwards corners of the world like Australia. Not 
that CDs have reached me properly yet anyway, since I'm here 
talking about cassette tapes, but with the boombox set up with my 
TV, I can switch its input over to the PlayStation 2 I use as my 
video file and DVD player, and that plays CDs too. Even MP3s if I 
want to go really 21st century. It's even another Sony product!

Oh well, almost mid-day now after all that rambling and the fog is 
only just starting to lift. I guess I'll see if it's much better 
outside but I suspect todays gutter disasters will be put off until 
after lunch. Ping is still showing 55% of my internet data packets 
are getting lost in the fog, so I guess I'll have to upload this 
some other time. Another distraction for later...


Back again to upload this on Monday, and sure enough late to start 
work again as a result... Got that bit of shed gutter refitting 
done yesterday at least, well that little part of the overall job 
anyway. I've uploaded some photos. No time to link them in with the 
text above so you'll have to match things up yourself. Also a photo 
of the FH-7 in its new home on a straining flat-pack shelf next to 
my TV. Out of its boombox configuration though, with the speakers 
and handle detached:

gopher://aussies.space/1/~freet/photos/teardowns/sony_FH-7_mkII/

If you're a sucker for comparing different engineering approaches 
like I am, you can also compare it with these photos I uploaded 
years ago of the comparatively basic insides of one of my more 
typical garage-sale boombox finds (suffering from a much more 
obviously perished belt). A Panasonic RX-4950 that I fixed up for 
Mr Ebay:

gopher://aussies.space/1/~freet/photos/teardowns/Boombox_Panasonic_RX-4950/

 - The Free Thinker