Forums :: NEW! Web Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Oct Sun 25, 2020 6:37 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 16 posts ] 
Author Message
 Post subject: Cheap China bt receiver
PostPosted: Jul Thu 16, 2020 2:14 am 
Member

Joined: Jul Wed 15, 2020 12:49 am
Posts: 102
Why all the hubbub with transmitters? I contemplated getting one, or something similar, but didn't want to fork over the cash. Yes, it would be fun building one, but alas, the forking over of greenbacks for components still didn't settle well. So about 2 years ago, I found some cheap Bluetooth receivers; I bought 2 Chinese units for less than $8 for both. Proceeded to connect them into the volume pots via original caps in the circuits of the Philcos 38-1 and the 42-400. Dug through my old cell phones- had 3 that actually still charged up and proceeded to link them up. As expected, volume was considerably lower than the radio. So, I went online to see if I could turn the volume up internally. One phone in particular took favorably to this, and volume was quite noticeably higher, but still not as loud as the radio. So I went online again and tried a free volume booster app. BINGO!!!!! The 38-1 kicks proverbial a**. Just as loud and crystal clear as the radio itself, which in itself is BREATHTAKINGLY AMAZING!!!!!
The 42-400 isn't quite as loud as the 38-1, but there is a small issue with that one; going to order new caps for it again (redone 8 years ago, recently developed a light hum). Still, she will ROCK THE HOUSE DOWN with serious good sound!!! All in all, I am tremendously happy with this set up. WIFI to an obsolete $30 phone with an app. When I play Utube, I get the added bonus of watching vintage videos along with my old music. EVERY SINGLE PERSON that experiences this is just floored. The volume adjustments are operable at the radio AND phone, like a gain control. Tone adjust at the radio. I even tried an equilizer app, but prefer the basic boost app. which I run at 38% boost on the 38-1, and 42% on the 42-400. Works perfect and woos EVERYONE!!!
Hint: the dumpy phones worked fine, but only the more expensive one ($35 as I recall. Ha.) opened up better internally, had more settings to play with. I'm sure others do this, but not from what I've seen... 8)


Last edited by Electrowight on Jul Thu 16, 2020 4:40 am, edited 4 times in total.

Top
 Profile  
 
 Post subject: Re: ss trans? Who needs it?
PostPosted: Jul Thu 16, 2020 2:40 am 
Member

Joined: Jun Sun 15, 2014 5:37 pm
Posts: 637
Location: Montreal, Quebec
People want to use their radios, but now often content is lacking.

Your way only uses the audio amplifier in the radio, might as well start with an "antique " amplifier rather than radio.

They aren't using low power transmitters because they didn't know how to add an auxiliary input jack.


Top
 Profile  
 
 Post subject: Re: ss trans? Who needs it?
PostPosted: Jul Thu 16, 2020 3:08 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 8691
Location: 13 Critchley Avenue, PO Box 36, Monteith Ont, P0K 1P0
It's not really the same though is it?

I'm not knocking it if it's what floats your boat, but it's more like plugging in a phono than receiving a radio signal. It eliminates the entire notion of an antique radio that receives radio signals from air, and treats the set as if it was just an amplifier.


Top
 Profile  
 
 Post subject: Cheap China bt receiver
PostPosted: Jul Thu 16, 2020 4:10 am 
Member

Joined: Jul Wed 15, 2020 12:49 am
Posts: 102
It was not my intention to knock the ss trans in particular, as I've never had or even seen one. I've heard the name dropped like it was a generic term, as a Hoover once referred to all vacuums to the public at large. I suppose I can delete this whole post or change the name if it is offensive. I just thought it was cool, as old music IS coming thru an antique 11 or 12 tube set, albeit only using 2 or 3 tubes. The average Joe sees an actual antique radio and hears old tunes eminating from it. They don't care if it uses 3 tubes or 12. Switch it back to BC band with all 12 tubes cooking and watch them clear out. Sometimes I do crank the am band with Paul Berlins' broadcasts on Sundays. That makes them run for the hills.
Again, if this offends any sensibilities, just say the word and I'll remove it in a New York minute and this will be the end of it.


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Thu 16, 2020 7:21 am 
Member
User avatar

Joined: Mar Sun 22, 2020 5:56 am
Posts: 834
Location: Arvada, CO
Over here in the Denver area, we are lucky to have some decent AM music stations (810 KLVZ, 1430 KEZW and 1390 KNGU on Thursdays at 9PM. Any one with me?). FM though, is pretty much trash content wise except for a few stations with some songs. Over in Los Angeles, they have 1260 KSURF for good music. For talk radio here, 560 KLZ, 630 KHOW, 710 KNUS, and 850 KOA are all pretty good, if you like that sort of stuff. KOA is the best for news. Over in Los Angeles (again) 1070 KNX is king.

_________________
Electronics are filled with smoke. It’s my job to put the smoke back in when they fail.


Top
 Profile  
 
 Post subject: Re: ss trans? Who needs it?
PostPosted: Jul Thu 16, 2020 12:49 pm 
Member

Joined: Jan Thu 16, 2020 12:29 am
Posts: 779
One reason why people want AM radio transmitters is that if these transmitters are designed properly, they generate modulated radio frequency carriers that a vintage AM band radio can tune in to, so as give the impression, using the vintage radio, that there is a "station out there" transmitting as they once did, in yesteryear, when the radio was in its heyday and people tuned into stations to hear the music or other content.

The only problem in my view is that I have yet to see any commercial AM transmitter kit that comes anywhere near close to transmitting a modulated signal close to the controlled and quality, the way it was once transmitted by an AM radio station. The defects are numerous, the main issue is a lack of audio level compression prior to the modulator, the lack of a linear modulator, a poorly designed RF output stage and poor antenna matching and bandwidth properties.

If you actually stop and listen to a real AM radio station transmission, you will find that regardless of the song they are playing the audio level sounds similar. This is because the source material (which is widely varying in level or average sound energy) has passed via a compression system, to level the average volume, and on top of that the modulation is carefully controlled (in a linear modulator too) to prevent over-modulation, and there is a soft clipping system to prevent the latter.

Every hobby AM transmitter system I have seen for vintage radio enthusiasts has been "hopeless" for the design for the important parameters to make a good home AM transmitter. So much so I had to design my own system with adequate volume compression and modulation control, linear modulation and a reasonable linear RF output amplifier with proper antenna matching. I have published some of these designs on other threads.

So when I hear stories about people getting poor results with commercial AM "Pantry transmitters" it never surprises me at all and I can see why some people resort to injecting audio signal voltages into a vintage radio's audio amplifier stages, getting much better results there. But really it is comparing that result to the "hopeless array of AM transmitters" that are out there, that have totally ignored the required important features of a proper AM transmitter, to get the transmitted signal to the "uniformity and quality" of that which comes from an actual radio station.


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Thu 16, 2020 3:14 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 9467
Location: Beaver Falls, PA. USA
It can be done! For 15 years, I have been using a Part 15 radio station that is every bit as good as a commercial station. Besides a decent transmitter, you will need to use audio processing and equalization. As a former broadcast and theatre-sound engineer, I had access to some old equipment. I'm using a CBS Audimax compressor and the companion Volumax limiter, with an Altec graphic equalizer. For those using a computer as a program source, there is software available to do audio processing. I'm one of those "old school" guys, who likes to do things the analog way. My system is based on CDs as program material, using a couple of Sony changers, feeding an Altec mixer.

I'm using an old LPB transmitter, feeding a leaky coax antenna, terminated with a dummy load. However, one does not have to go to that level; many folks here have built small transmitters that work well. They can be found in the home brew forum.

_________________
Tim KA3JRT


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Thu 16, 2020 5:06 pm 
Member

Joined: Jul Wed 15, 2020 12:49 am
Posts: 102
Thanks to everyone for setting me straight on this matter. I understand the reasoning now for wanting an actual transmitter as opposed to this. Funny thing is when I first hooked up the Bt, it kind of DID feel like I was cheating a bit. It just didn't feel right to me, almost fake, but once I was able to get the signal to a listenable level and then family, friends and neighbors heard it cranking out in the garage, all bets were off the table. Their utter shock and amazement that a 1938 radio was blasting actual music- ANY music- as opposed to some inane talk show was nothing short of astonishing to them. I wracked my brain trying to find a solution for a CHEAP alternative. CHEAP being the prime word here (as opposed to being my middle name). I made a cursory scan of what was out there, and ZERO of them fell within my budget. It was either this, or suffer the insufferable talk shows and Mexican music (Which comes thru quite well on about EVERY SECOND or third CHANNEL! UGH!!!)
Again, wasn't my intent to knock a product here or anyones' livelihood. Just presenting an alternative. :oops:


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Fri 17, 2020 1:40 am 
Member

Joined: Aug Mon 17, 2009 4:11 pm
Posts: 3534
Location: DFW Texas
How dare you use a BT receiver with these old radios. Have you no respect man? You should be drummed out of the club.
And furthermore you can never play any music that was released more than 10 years after the manufacture date of the radio. If you do we will send the music police to your house to comfiscate all your soldier.

_________________
The lucky ones realize the "Good Ole Days" while they are still in them!
AA5LP


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Fri 17, 2020 1:51 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 8691
Location: 13 Critchley Avenue, PO Box 36, Monteith Ont, P0K 1P0
Dennis H. wrote:
How dare you use a BT receiver with these old radios. Have you no respect man? You should be drummed out of the club.
And furthermore you can never play any music that was released more than 10 years after the manufacture date of the radio. If you do we will send the music police to your house to comfiscate all your soldier.


You bet !!

And furthermore ..... your soldier will be confiscated by uniformed solders.

So there !!

:)


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Fri 17, 2020 4:11 am 
Member

Joined: Jul Wed 15, 2020 12:49 am
Posts: 102
GADS AND GADZOOKS!!! I shall immediately cease and desist with Bluetooth operations!!! I shall take it under supreme advisement and disconnect the infernal, blasphemous device!!! That will leave but only El Mexically muzak, or worse, *ULP* R R R R u S h LL i m ba. uu.
RR u... AWW, C'MON GUYS!!!!!
Actually when the house is empty, only then am I allowed to listen to terrestrial radio. Which I do. The tv goes off immediately and they get cranked wide open. AM or shortwave, it matters not. When I got the 38-1 running and before the Bt, the tv went on a total of about 4 hours in 2 or 3 months time, running the chassis on the cold tile floor, with a huge heatsink with built in fan on the candohm side and a fan blowing constantly on the transformer and hot spots, of which there was none with the aforementioned heatsink(s). That sucker played 38 hours straight after the first night, with a transformer running so cool that you could put and keep your tongue on. And yes, The 38-1 has logged over 4,000 hours of playtime since I got it running Dec. 25, 2017!!! You heard me right!!! Not long after that mark, I stopped keeping track. Lol.
And yes, I listen to 30's and 40's music over Bt. (but man, Iron Butterfly and It's a Beautiful Day live vibrates the paintings on the wall in the other room just perfectly swell)
!!! And just for the record, I've done absolutely NOTHING else to it, save the Bt. since the rebuild. Plays perfect. 8)


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Fri 17, 2020 4:35 am 
Member

Joined: Jul Wed 15, 2020 12:49 am
Posts: 102
And be it known for the record that in MY book, removing a real chassis and replacing it with a full bore Bt. system IS blasphemous, treasonous, insulting, disgusting, revolting and base. I throw myself upon the mercy of the court... :wink:


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Sun 19, 2020 11:27 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 5379
Location: Black Hills, SD 57745
:mrgreen:


Attachments:
WimminAndBThatersClub.jpg
WimminAndBThatersClub.jpg [ 156.96 KiB | Viewed 1332 times ]

_________________
My life is loosely based on a true story.
Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Mon 20, 2020 2:36 am 
Member

Joined: Jul Wed 15, 2020 12:49 am
Posts: 102
^^^^^ :D
And man, dig dat crazy horn radio!!!
What a most excellent club!!!
Sign me up...
The sign says it all!!! :P


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Tue 21, 2020 12:15 am 
Member
User avatar

Joined: Sep Thu 14, 2006 3:27 pm
Posts: 13094
Location: Carmel, Indiana
Electrowight wrote:
Again, if this offends any sensibilities, just say the word and I'll remove it in a New York minute and this will be the end of it.


I don't think your suggestion really offends anybody, it just may not interest a lot of people in the antique radio hobby. I think some people, including myself, believe that bypassing the tuner portion of a radio kind of takes out the fun of listening to a radio in the first place. Tuning in stations is part of the fun and if you can tune in programming from a personal transmitter, all the more fun. Your suggestion of adding Bluetooth to the audio section is more popular and accepted with the younger "Mid century Modern/Danish Modern" console stereo crowd then it is with the generally older antique radio crowd, that's all.

_________________
Michael Feldt
www.indianaradios.com


Top
 Profile  
 
 Post subject: Re: Cheap China bt receiver
PostPosted: Jul Tue 21, 2020 3:18 am 
Member

Joined: Jul Wed 15, 2020 12:49 am
Posts: 102
I am willing to try it. I will look up the plans to build a transmitter, and if it's not too dear (in my budget, it's a certainty that it will far exceed any "dearness" realm) will attempt to fabricate such an device. It would be quite a pleasant experience to tune right back into 1938. Been working on a time frequency generator, but alas: budget shortfalls and all that rot, you know... :mrgreen:


Top
 Profile  
 
Post New Topic Post Reply  [ 16 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 13 guests



Search for:
Jump to:  
cron


































-->


Privacy Policy :: Powered by phpBB