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Well I had made a long post and side or internet crashed and lost it all.
So I will re do it but shorter.

I use the big system almost everyday, the portable one I don't really use them any more.
I have a antenna 70' up for the radio I get station from Cornwall, Montreal. Ottawa and Hawkesbury. I live to drop the needle on the record was listening to some good classic rock at time of photo.


I got new mixed up with old and very old some of the stuff is 1 week old and other parts are 30 plus years old.

I can stream from the net, mp3's from ipod record and radio from this good combo, the black Sony is new only 1 week old lots of inputs and great tunner on it.
















well here it is if you look on my Photo Bucket you will see I have uploaded a few more
all quality you know how to make them bigger.
 

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sorry for the dust, but I just put everything in this old case I had everything on a old computer desk like my other systems, computer desk are good for more then computers.
 

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Amazing pic! Especially the vintage "CSA" certification sticker... :)

Some of the older tube receivers had amazing AM sections.

And the tube amps were quite "warm" in the sound department. They tended not to distort when over-driven but gently compress...

And in cooler climates / houses provided an alternative heat source.... :)

Cameron
 

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Discussion Starter #44
Battery cover - made for JVC RC-250C radio.

OK - some pictures now.

Here's a picture of the radio, a JVC Radio Cassette Recorder model RC-250C.

It's a fairly old model, I'm sure. I'm guessing 1970's or 1980's.
But it has good reception / features and is fairly portable.

I needed to make some sort of cover for the battery compartment in the bottom, or else the 4 D cells fall out. Cover was missing when someone gave me the radio.



Details off radio:

JVC Radio Cassette Recorder
Model No RC-250C
AC 120V 60 hz 4W
DC 6V
4 D batteries

Victor Company of Japan Limited, Made in Singapore.
CSA - home entertainment device F 253086
[CSA, Canadian Standards Association safety cert file no. - might be able to get more info on the radio from this ... not sure ]

Features:

Top of Radio:
Cassette Tape recorder push button controls.
Mic Jack
Selector switch: Radio off, Tape / MW [AM] / SW / FM
Knobs: Tone low/high / Volume
Small dial: Fine tuning

5 section whip antenna: 38" / 96 cm total length extended.

SW is 6-18 Mhz
FM 88-108
MW [AM] 54-160 KHz x 10

Back of Radio:
switch in center: Monitor ON/OFF [ you can shut off the speaker, if you wish, for example if recording and do not wish to hear the radio ]

Earphone jack.

Side of Radio:

Main tuning dial
Connector for removeable AC power cord
Connector for 6V DC AUX power input

... there's more pictures in my album, but I won't post them all here, just a few more to show the battery cover I made, next posts.
 

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Discussion Starter #45


This is the cover I made, of clear plastic, to fit, nestle in exactly into the rectangular hole where the previous lost cover was. Some yellow pieces of compressible foam like sponge (scrap carpet underlay) are glued to fill open space and keep batteries tight and not rattlilng around.




The clear plastic was a little thicker, and extended a little past the bottom surface of the radio, so I carefully machined some rounds down a little where I was gonna mount the screws. That will drop the screws down flush, make them hold properly, and hold the cover in place too / prevent it from moving or sliding out.




Here it is mounted in the radio, 4 screws cut short. They are automotive trim screws from Canadian Tire auto section - because they are wider at the head and have an incorporated washer in the head to grip further.
 

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Discussion Starter #46


Adding the screws to the bottom of the radio had a consequence. They stuck down further than the feet of the radio, so the radio would not sit correctly, would not be stable, would fall over more easily, and the screws would probably scratch up any surface you put the radio on.

So I had to get creative and make new feet to raise the radio a little higher to clear the screw heads.

I did it like this, by simply gluing up some more pieces of the same clear plastic and building up legs a little higher.

Over all NOT a NICE LOOKING repair - but works, and sits under the radio so you really don't see it.

Getting a cover to work exactly like the original, to click in/snap in like the original, and look good - was not going to be easy.

So that's the best I could do ... with what I had at hand.

More pictures of the radio / different views, in my album ...
no need to post more pictures here.
 

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Earlier to middle 1980s I reckon.

My brother had one of those mono boom boxes, a little bigger than that.
Despite being Pulser brand (Canadian Tire store brand for electronics), it worked remarkable well. That one was basically a tape recorder with radio (the amp chip was the same as a Lloyds tape recorder we had. One interesting thing was the radio was tuned so that FM 98.7 and AM 740 were the same place on the dial, and you could flip the band between AM and FM. and get CBC AM Toronto, or the CBC Wiarton transmitter.
 

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4KTV, I like that one, looks pretty good....
here's a couple more I was working on today. Almost done with them, a few parts left to replace in both.

A zenith C730 (chassis 7C05) whose finish was trash, so I put some veneer samples on it.
Didn't come out very well but I wasn't expecting it to either.
https://db.tt/COOykQLZ

A Magnavox FM-18 (chassis # 580100)

https://db.tt/b3a9Wvr3
 

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The Zenith C730 in the previous post, replaced the selenium rectifier with a 1N4007 silicon diode. When ya do that it is recommended to add some series resistance to it to replicate the roughly 20 V drop across a Selenium rectifier. Goal being to get the B+ back down to where it was designed to be, but may take trial and error to get it right. Can't quite see it, but the lower right, the terminal strip I added to wire in the silicon diode is where the selenium was.

https://db.tt/0ALIxjiM

a pic from underneath
https://db.tt/79mOJ9c4

and last problem...
a pic of the FM RF & FM Osc adjustment slugs,
https://db.tt/OumTjLjV
These move up or down driven by a cam, when tuning FM. Originally was way off on FM with half the dial completely missing and stations in the wrong location.
Had to be aligned by turning them long spring/screws that go thru the center of each slug. Was a common setup in the frontend for Zenith AM/FM radios of that era.
Much better now...
 

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This is the first really old radio I ever had. Just got done fixing it up. Working good on all bands. I bought it ~ 1990 or so at a yard sale down the street.
It is a Zenith model 7S-529 from ~1940 or 1941

 

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The good old days of analog when I decided exactly where the volume should be by tiny turns of a volume control knob (potentiometers), not in digital increments decided by some 8 year old in knee pants in some far off galaxy.

:p sailmaker
 

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Nice set. I've never seen one quite like it. Those 1940s multi-band short wave sets have a great look. I played around with a few of those in my younger days. Sometimes got in trouble for it too. Are those mechanical presets on the bottom?
 

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Yes and they do work... I have them dialed in to some favorite local am stations.
some more info courtesy of the radiomuseum.org website.

http://www.radiomuseum.org/r/zenith_7s529_chassis_7a02.html

They are well known for using rubber insulation that crumbles to pieces, making it necessary to completely rewire the thing. Very tedious, but doable... Along with the infamous 6X5G rectifier that fails and causes the Transformer to be destroyed. Both issues are very common to Zenith sets of this era. Mine was no exception:)
I just got done recapping it, replacing some crumbled wiring in the process, along with a new AC cord.
 

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I have a pretty good idea of what you are dealing with. Tried to fix a few tube radios back in the 1960s. Nothing quite this nice though. Wax caps don't last long and they are messy. :eek: Neither those nor rubber insulation like heat much and their is lots of it in these tube sets. Hope you get it working well and enjoy listening. :)
 

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Not sure what happened to the picture in post #53. Must be an issue with 'community albums'

here is another one someone dropped off to me yesterday.
Silvertone Model 1841 (possibly was made for Sears by Atwater Kent??).
AM / SW.
It is not as tall as it looks. Gonna need grill cloth and a wooden knob for it.
Got it playing well already today.
 

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A search turned up nothing about crystal radios at this forum - such as my 1958 Heathkit CR-1.

For sure, this kit does not have a crystal and a cat's whisker needle to feel-out the rectifying spot on the diode. The kind I remember from my childhood - and still a great learning experience for kids today. It has a germanium diode.

The Heathkit has two tuning capacitors and a switch to switch-in two more fixed capacitors for tuning, none of them ganged. Works good!

At the University of Chicago, we strung a few hundred feet of wire out the 3rd floor apartment back porch and into a tree and got reception from hundreds of miles away.

I believe I hooked it up to my HiFi and got excellent sound, atmospheric static excepted. The sound with the primitive headphones was OK too, if not "crystal" clear.

Question: is the sound from a crystal radio truly HiFi in the sense that it is a pure demodulation of the radio wave with no active elements?

eBay has these sets for around US$50 plus shipping.

Ben
 

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Crystal sets provide maximum fidelity for AM but that can be improved upon. That's because the RF circuit in crystal sets are not very selective. Using active components to improve selectivity will improve reception and block out interference without affecting frequency response. There is lots of research that was done on this many years ago. The AM radio band is very limited in the fidelity it can provide. That's due to the 10KHz channel spacing and the limits imposed on bandwidth that AM stations are allowed to use in transmission. The FM band is an improvement but it also has limits in practical use. The digital FM standard is no better, actually worse in practice. It's almost impossible to find really good fidelity in any broadcast medium. That's reserved for things like DVD audio, SACD, Blu-ray audio and some HD audio digital formats that must be purchased. Even CD audio is a compromise but it's better than most broadcast and streaming formats.
 
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