Classic Rotary Phones Forum

Other Telephone Information => Off Topic => Radios & TVs => Topic started by: 19and41 on December 11, 2015, 03:30:51 PM

Title: Magnavox Hepplewhite
Post by: 19and41 on December 11, 2015, 03:30:51 PM
I just got my first console radio, a 1947 Magnavox 153B.  It has an AM and shortwave receiver with an optional FM tuner in a album cabinet.
Title: Re: Magnavox Hepplewhite
Post by: andre_janew on December 11, 2015, 05:23:04 PM
I didn't realize they had FM radio in 1947!
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on December 11, 2015, 05:34:19 PM
The FM process was patented in 1933.  Here is a summary of it's early history.

https://en.wikipedia.org/wiki/FM_broadcasting_in_the_United_States
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on January 01, 2016, 12:17:01 AM
Finished restoration on the receiver and speakers.  the unit is a good performer.  Here are pics of the tuning indicator tube in the open position and the closed position that comes with a tuned in station.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on February 11, 2016, 01:58:39 PM
I've put up an antenna hidden in the soffit, and the shortwave reception is pretty impressive.  I have gotten radio Romania, China, Havana, Australia And a number of others with no English programming.  The amp gives decent fidelity with the FM receiver and Mp3 input.  It has really been fun playing with it.
Title: Re: Magnavox Hepplewhite
Post by: ..... on February 11, 2016, 02:55:43 PM
That's a very nice piece you have there. Looks good.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on February 12, 2016, 04:55:30 PM
Thanks!
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on March 06, 2016, 06:34:19 PM
Here is a pic of the 2 10 inch field coil speakers they are driven by a 22 watt push pull amp.  There was a bit of abrasion damage on one speaker.  I put a strong patch on the damaged area .  You can see it on the left.

Title: Re: Magnavox Hepplewhite
Post by: 19and41 on March 06, 2016, 06:38:02 PM
Here is a schematic diagram of the receiver/amp. I changed the FM audio connectors to RCA jacks from the period multi pin connectors.

Title: Re: Magnavox Hepplewhite
Post by: 19and41 on March 06, 2016, 06:45:13 PM
and this is a schematic of the FM converter used with it.  Both this and the receiver/amp required replacement of all their paper and electrolytic capacitors.

Title: Re: Magnavox Hepplewhite
Post by: 19and41 on March 22, 2016, 05:12:25 PM
I got a RFI line filter that has cut the amount of spurious noise on the radio.  I was able to get Radio Prague between 5 and 7 pm while it was still daylight.  Just as strong and clear as the nearby AM stations. 
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on September 07, 2016, 02:45:13 PM
I finally went to Home depot and got a post driver and a 1/2" 8 foot ground rod and sank it below the antenna lead in then ran some #8 wire from it to the shielding of the RG-6 I lead the antenna in on.  This reduces the RFI on the noise floor and allows for greater sensitivity across the short wave and AM broadcast bands.  Radio Havana comes in like it was coming from Atlanta.    I have had to do a replacement of the 15Mhz oscillator trimmer as the creatures that rented the interior before I purchased the radio leaked a little on it.  Surplus Sales Of Nebraska had a good replacement in both size and value.  I still need to do an over the air adjustment on the antenna trimmers to accommodate the new ground setup.  This thing has been mighty fun to work with since getting it!
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on November 17, 2016, 05:46:01 PM
I've been listening to it regularly, and I get good reception from stations in both Europe and Asia.  The ground made a good improvement in it's reception.  The main stations I get regularly are ABC Australia and Radio China.  Radio Slovakia and Radio Prague come in  very well in the early evening, among other stations.  Radio Havana has a few good programs as well.  This thing has been a lot of fun for a $50 initial investment, sold to raise money for breast cancer research.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on January 10, 2017, 08:51:03 PM
The bad storm that passed through last weekend has apparently gotten moisture into the outdoor portion of the coax line to the antenna.  I am getting ground feedack on the antenna line.  It will need a disassembly and hot air treatment.  I messed up and didn't put synthetic grease into the grounding break I put into the antenna line.  Act in haste, repent in leisure.
Title: Re: Magnavox Hepplewhite
Post by: Phonesrfun on January 10, 2017, 10:48:38 PM
Unfortunately, water in coax is pretty bad.  If it is significant, coax can act like a pipe and I have seen situations where water will actually drip out of the inside end!


Water also destroys the properties of coax, and can't really be dried out effectively.    You might be replacing it when the weather gets better.  I learned the hard way that one DOES NOT want to transmit using soggy coax.  It has a tendency to act like a short to final amplifiers.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on January 22, 2017, 05:54:22 PM
Over the last couple of weeks I have gone through the system.  I opened and checked out the antenna connections under the eaves and everything looked just great.  I put synthetic grease in the connections as a preventative measure.  So I was left with Horrible RFI across the bandspread.  I pulled out the receiver and checked for any distorted electrolytic filter caps.  Darned if I didn't see one of the original filter caps still in the circuit.  I'd left it by mistake during the restoration.  I had disconnected them and left them in place to have the unit look original.  I disconnected this one and installed new filter caps.  Still horrible 60Hz RFI.  So, I went through the house with the radio on, volume up, pulling the plugged in circuits one by one.  I got to the wall supply for my digital cable box.  I pulled the plug in the box and the noise dropped by half.  I pulled the supply from the wall and it dissapeared.  I dug through my odds and ends and found another supply to graft onto the coaxial connector.  The radio now works better than ever before.  I listened to WOWO, WSM, Radio China, Radio Havana and KBC International, all as clear as Atlanta.  I put up a pic of the console on The KBC site.

http://www.kbcradio.eu/index.php?dir=gallery

Title: Re: Magnavox Hepplewhite
Post by: 19and41 on February 02, 2017, 01:34:50 PM
The AM reception has been good enough that I have been able to start putting the station presets on to the stations they were originally labeled for in the Chicago area.  It is getting KMOX really well.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on April 19, 2017, 02:42:40 PM
I am now in the process of setting up a period turntable in the console.  I have bought an old Webster-Chicago single speed 56-3 for it.  I have had to get the isolation springs to mount it and a start button.  I thought I would do a trial fitting and found that the sliding mount for it had been heavily modified, to the point that it is unusable with the turntable.  I put up a want ad on the radio forum, and will be having another mount shipped shortly.  It's more expense than I wanted to put into this portion of the unit, but there you are.
Title: Re: Magnavox Hepplewhite
Post by: HarrySmith on April 19, 2017, 08:24:51 PM
Very Cool!! Keep us updated please. Don't forget pictures!
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on April 25, 2017, 01:30:59 PM
It looks like the frame is on the postmans' truck for delivery today.  I may be able to get pics of the ratty one and the "new" one in the next couple or 3 days. I'll use the new one as the test stand for doing the clean and lube on the turntable.  I am ordering a replacement type cartridge/stylus for it.  I had hoped to renew the Idler wheel for the platter drive, but the rubber on it doesn't seem to have the ability to absorb the super lube like many other items do.  That may be an iffy prospect, as I want no wow on the thing.  I dug up two RCA 78 album collections that I had neglected to get rid of and they appear to be in very good shape.  One is 4 swing bands, the other is Glenn Miller standards.  4 discs each, 8 sides.  mighty puny compared to the Mp3 library I am now used to.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on April 26, 2017, 03:49:15 PM
The frame arrived without damage.  The first photo shows the frame in the console, modified to the point of ruination,  The second shows the replacement frame.  Note the mounting point to the right, missing in the gray original.

Title: Re: Magnavox Hepplewhite
Post by: 19and41 on August 30, 2017, 01:46:30 PM
While the turntable project is on hold for the eventual purchase of a welder to make the graft from one frame to the other,  I am still casting about on the AM/SW receiver evenings seeing what I can bring in.  I have recently gotten NHK Japan, the Voice Of Vietnam and am still getting Radio Havana Cuba, as well as blowtorch Radio China.  On the AM side, I was able to get WOWO pretty strong.  For some reason it is usually a difficult station to get.  KMOX comes in better.  The difficulty in getting genuine stations on SW is that a number of stations are rebroadcast here.  I have to keep checking the frequency I get them at with online lists to make sure they aren't retransmissions.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on September 20, 2017, 03:41:40 PM
Some mornings, when I wake too early, I'll see what I can tune in and a bit over a week ago, I got an English speaking station.  They were doing the news and mentioned Wellington and Christchurch.  The Latter I had only heard associated with New Zealand, on the opposite side of the earth.  After checking the frequency to see if it might be the origin, It worked out to be Radio New Zealand International on 7425Khz.  I went online and filled out a QSL form and I Just got confirmation from them today.  My first QSL using a 70 year old console shortwave.
Title: Re: Magnavox Hepplewhite
Post by: AL_as_needed on September 20, 2017, 10:05:20 PM
How exactly did you lay out your antenna? From what I gather you ran a long wire loop through the eve under your roof? I have had one of those "slide ruller" type 8 band radios for years now and it works ok.... but its not nearly as precise or sensitive to really grab a good signal.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on September 20, 2017, 11:11:04 PM
It is a single stranded wire laid in the bottom drip cap of my eave cover. It is 55 ft. long and is connected to an RG-8 cable with a earth grounded shield, grounded to an 8ft. ground rod.  It is oriented east-west.  I wanted something along the line of what would have been used with the console when new, in 1947.  It has definitely been worth the effort to set it up.
Title: Re: Magnavox Hepplewhite
Post by: AL_as_needed on September 21, 2017, 09:26:28 PM
That actually seems fairly simple despite the tedious bit of sneaking the wire into the flashing. I one day would like to get a helicrafters or similar but dont really have the room to set up a dedicated aerial on a pole or anything too involved.

My parents have a old zenith consol that at one point was wired to the copper radiant base-board heating pipes, worked surprisingly well.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on September 21, 2017, 09:53:33 PM
You could go on Ebay and find an old wire loop antenna from a console radio to use as an antenna.  Hallicrafters radios are pretty good performers as long as the coupling capacitors in the IF transformers are not damaged.  They can be found at a wide range of prices.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on May 10, 2018, 02:58:52 PM
The shortwave reception petered out in November and I have checked from time to time to see what's up.  Yestderday morning I barely got Radio New Zealand again, so I left the tuner where it was and shut it off. just turned the radio on and this morning I got it understandably.
Title: Re: Magnavox Hepplewhite
Post by: AL_as_needed on May 10, 2018, 08:07:07 PM
What do you think is/was the cause? Weather related conditions disrupting signal strength?
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on May 10, 2018, 09:55:24 PM
I'm getting the impression that it may be a seasonal kind of thing.  A couple of years ago about this time of year I was able to get the Radio Australia service about the same time of morning (7:30 to 8:30 am EDT). 
Title: Re: Magnavox Hepplewhite
Post by: rdelius on May 10, 2018, 10:24:37 PM
Schedules change by season. Australia turned off shortwave broadcasting several monthe ago.I  have  nice shortwave equiptment bur not much to listen to anymore.
Title: Re: Magnavox Hepplewhite
Post by: 19and41 on July 17, 2018, 06:33:35 PM
I had a near miss Saturday.  I just finished mowing the lawn and it started raining, then suddenly started lightning.  Before I could do anything, I saw a silent flash outside with a loud snap at the rear of the console.  I reckon there was an induced voltage spike on the antenna line to ground.  I couldn't find any damage.  I disconnected and left the antenna lead in.  I reconnected it Sunday and tried the shortwave.  I got Radio Romania for the first time and a station that usually plays middle eastern music had an english speaking broadcast.  I couldn't get identification.  There were quite a few stations that I could get.