Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Transistor Radio

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 06-25-2014, 11:37 AM
Ishmael Ishmael is offline
VideoKarma Member
 
Join Date: Jun 2014
Posts: 9
Earth Orbiter-Grond Control to Major Tom

Good Morning, this is a first post. Recently I came across a Sony “Earth Orbiter” CRF-5100 10 band radio. It really brought back memories, and it was so cool looking that for $6.00 I went ahead and made a purchase, as even if it didn’t work just looking at it made me happy. Imagine my surprise when I got it home and found it worked and could pull in an AM signal, no FM, through a scratchy volume control. The lights worked, and it has the original AC power cord. Another cool moment was finding that the signal strength LED on the dial pointer lit up (you can see it in the picture below) and changed brightness as the signal strength increased or decreased (it also has a signal strength meter/but the light may be out on it, if it has a light?).

Other than our Sansui TU-717 I am a complete novice regarding the various bands on this radio, so here are my questions, and my thanks for any help you can provide:
1. Is there a good reference book, e.g. easy for a novice to read and understand, that explains what the various bands on this radio are for? For example there are 5 short wave bands with names like “SW5-International BC/Amateur”, “SW3-International BC”, “SW2-Domestic BC/Amateur” and “SW1-Marine/Tropical”.
2. In a similar vein, is there a good reference book, post, Youtube that explains the operation of the “Squelch”, “BFO” and “RF Gain” controls that are on this radio?
3. While I have found a CD service manual for this radio on Ebay I have not found an owner’s manual, are there any other suggested sites where I might find an owner’s manual for this radio?
4. This radio can accept external antennas, one for “SW” and “MW/LW” and the other for “FM,AIR,PSB” are there better/worse antennas you would recommend for these different bands?
5. Finally, I live in the Pacific Northwest and am a novice as it pertains to electronics. Given the nice condition this radio is in, and that it works, I would really like to take it to someone who could do a good job of cleaning, calibrating and servicing this radio. While I want to enjoy it in the years to come I plan on gifting it to a grandchild in a couple years so that they can discover the wonders of the real world. Any thoughts, suggestion on who I could take this radio to?

My thanks in advance for any help you can provide, I hope you enjoy the pictures attached. Looking at the back it appears it was only used on AC cord as the battery bay is pristine, except for dust.
P1030914.jpg

P1030919.jpg

P1030915.jpg

Last edited by Ishmael; 06-25-2014 at 11:48 AM. Reason: Posted this in the wrong forum
Reply With Quote
  #2  
Old 06-25-2014, 11:49 AM
Ishmael Ishmael is offline
VideoKarma Member
 
Join Date: Jun 2014
Posts: 9
Sorry guys miss-read forum, this should go into the radio not TV forum, will try to amend.
Reply With Quote
  #3  
Old 06-25-2014, 11:54 AM
Ishmael Ishmael is offline
VideoKarma Member
 
Join Date: Jun 2014
Posts: 9
Earth Orbiter-Ground Control to Major Tom pt. 2

Good Morning, this is a first post. Recently I came across a Sony “Earth Orbiter” CRF-5100 10 band radio. It really brought back memories, and it was so cool looking that for $6.00 I went ahead and made a purchase, as even if it didn’t work just looking at it made me happy. Imagine my surprise when I got it home and found it worked and could pull in an AM signal, no FM, through a scratchy volume control. The lights worked, and it has the original AC power cord. Another cool moment was finding that the signal strength LED on the dial pointer lit up (you can see it in the picture below) and changed brightness as the signal strength increased or decreased (it also has a signal strength meter/but the light may be out on it, if it has a light?).

Other than our Sansui TU-717 I am a complete novice regarding the various bands on this radio, so here are my questions, and my thanks for any help you can provide:
1. Is there a good reference book, e.g. easy for a novice to read and understand, that explains what the various bands on this radio are for? For example there are 5 short wave bands with names like “SW5-International BC/Amateur”, “SW3-International BC”, “SW2-Domestic BC/Amateur” and “SW1-Marine/Tropical”.
2. In a similar vein, is there a good reference book, post, Youtube that explains the operation of the “Squelch”, “BFO” and “RF Gain” controls that are on this radio?
3. While I have found a CD service manual for this radio on Ebay I have not found an owner’s manual, are there any other suggested sites where I might find an owner’s manual for this radio?
4. This radio can accept external antennas, one for “SW” and “MW/LW” and the other for “FM,AIR,PSB” are there better/worse antennas you would recommend for these different bands?
5. Finally, I live in the Pacific Northwest and am a novice as it pertains to electronics. Given the nice condition this radio is in, and that it works, I would really like to take it to someone who could do a good job of cleaning, calibrating and servicing this radio. While I want to enjoy it in the years to come I plan on gifting it to a grandchild in a couple years so that they can discover the wonders of the real world. Any thoughts, suggestion on who I could take this radio to?

My thanks in advance for any help you can provide, I hope you enjoy the pictures attached. Looking at the back it appears it was only used on AC cord as the battery bay is pristine, except for dust.

P1030921.jpg

P1030918.jpg
Reply With Quote
  #4  
Old 06-25-2014, 11:57 AM
Ishmael Ishmael is offline
VideoKarma Member
 
Join Date: Jun 2014
Posts: 9
In the classic words of Bill the Cat "Aaaaachk" if you go to the "Transistor Portable Televisions" forum and look for my post "Earth Orbiter-Ground Control to Major Tom" you will find the other pictures I posted, but in the wrong forum. I think I got the right forum this time, thanks for your patience.
Reply With Quote
  #5  
Old 06-25-2014, 12:00 PM
Ishmael Ishmael is offline
VideoKarma Member
 
Join Date: Jun 2014
Posts: 9
I think I have posted this in the right place "Vintage TV & Radio Tech Forum"? Thanks for your patience.
Reply With Quote
Audiokarma
  #6  
Old 06-25-2014, 03:19 PM
bandersen's Avatar
bandersen bandersen is offline
RCA 741PCS
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 8,085
Hi and welcome to Videokarma. Nice radio but outside my area of expertise. Hopefully another member can help out.
__________________
Here are my Vintage Radio & TV YouTube Channel and Photo Gallery
Reply With Quote
  #7  
Old 06-25-2014, 03:58 PM
Ishmael Ishmael is offline
VideoKarma Member
 
Join Date: Jun 2014
Posts: 9
Thanks Bandersen, so far with the aide of google and wikipedia I've found some explanation for these controls, the BFO was interesting. If I am reading it right it turns a morse code signal into audible tones? Sorry won't be learning morse code, but it will be fun to listen in to.
Reply With Quote
  #8  
Old 06-25-2014, 04:10 PM
jr_tech's Avatar
jr_tech jr_tech is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 4,510
The BFO is also used to receive Single Sideband transmissions... those stations have a "donald duck" quality otherwise.
http://www.dxing.com/modesand.htm
Lots of good stuff linked from that Universal Radio site.
jr
Reply With Quote
  #9  
Old 06-25-2014, 06:22 PM
Ishmael Ishmael is offline
VideoKarma Member
 
Join Date: Jun 2014
Posts: 9
jr-tech, thanks for the link which I printed and added to my Earth Orbiter file. I will check out the various menus at the Universal Radio site. I figure the more I learn the more I will enjoy. Thanks again.
Reply With Quote
  #10  
Old 06-25-2014, 06:24 PM
Ishmael Ishmael is offline
VideoKarma Member
 
Join Date: Jun 2014
Posts: 9
The should be "Ground Control to Major Tom", Space Oddity David Bowie, oops.
Reply With Quote
Audiokarma
  #11  
Old 06-25-2014, 06:47 PM
Kamakiri's Avatar
Kamakiri Kamakiri is offline
Administrator
 
Join Date: Jun 2002
Location: Buffalo, New York
Posts: 5,109
I merged both threads and moved them to Transistor Radios
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia."
Reply With Quote
  #12  
Old 06-25-2014, 06:58 PM
loopstick's Avatar
loopstick loopstick is offline
VideoKarma Member
 
Join Date: Mar 2014
Location: Shit 'n' Piss, Texas
Posts: 56
Hmmm ... a little bit of new guy nerves, huh? Welcome to VK.

Here's that sticky I suggested:

Show us your portable AC/DC transistor radios!

You ask some good questions. Here are some quick hip shots:

1) Scratchy volume control: the usual "fader lube" not de-oxit electronics cleaner / lube spray, just like on AK.

2) Meter light: they would either not have them or make them switchable to save on batteries.

3) The bands are, well you know what they are. You might be able to stir up some hobbyist hits on the web by googling "Bob Grove", "Monitoring Times", that was the place to go before the internet, probably the same today, basically everything and anything multiband hobby. Not ham focused, just listener. Another magazine big back in the day was "Pop Comm" - Popular Communications. And many of us old timers remember the SW columns and articles in "Popular Electronics" which my high school library subscribed to.

4) Squelch, just like on a CB, cuts out the sound during empty background noise, BFO beat frequency oscillator, provides a signal to mix with either morse code or SSB. It "beats" against these signals like when you tune a guitar and you hear that low frequency wah-wah-wah error. This beat frequency is much lower than RF, (it's AF) and the programming (variation) basically gets shifted from RF (which we can't hear) to AF (which we can). Normal AM however provides its own BFO in the form of a transmitted RF "carrier". RF gain allows you to weaken strong stations and strengthen weak stations.

5) The antennas thing is a whole new discussion, there is a wide variety of approachs.

6) Cleaning and other maintenance: that's another discussion too. The main thing is that it works and these things are pretty reliable.

Last edited by loopstick; 06-26-2014 at 12:27 AM.
Reply With Quote
  #13  
Old 06-25-2014, 10:09 PM
Ishmael Ishmael is offline
VideoKarma Member
 
Join Date: Jun 2014
Posts: 9
Thanks for merging Kamakiri and loopstick thanks for your responses I will check out the web sites you mention and add your response to my Earth Orbiter file. I have a rapidly expanding Earth Orbiter file with a lot to read the next couple days, a good thing and greatly appreciated.
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:07 AM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.