Using a Signal Generator for an "In Home" radio transmitter - Page 2

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Re: Using a Signal Generator for an "In Home" radio transmitter
On Wednesday, January 9, 2019 at 9:48:36 PM UTC-5, Fox's Mercantile wrote:
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I have a 1930s-vintage Coronado chairside that looks like this:

http://antiqueradios.com/gallery/main.php?g2_itemId29%062 That calls itself  a dual band radio, being AM & Police/Aircraft. It is a single-band radio with the AM bandwidth expanded.  

The dial goes from 530 to 1790.  Police band back in the day was 1714. I have not been able to pin down Aircraft, but I expect somewhere below 1790.  

The radio is also unusual in that it had an acorn bias-cell - now replaced with a 1.5V AAA. Plays nicely.  

Peter Wieck
Melrose Park, PA  

Re: Using a Signal Generator for an "In Home" radio transmitter
snipped-for-privacy@myshop.com

1980s, AM extended up to 1700

Re: Using a Signal Generator for an "In Home" radio transmitter
On Sun, 13 Jan 2019 19:56:58 -0800 (PST), snipped-for-privacy@gmail.com wrote:
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In the western hemisphere...

"On June 8, 1988 a conference held at Rio de Janeiro under the auspices  
 of the International Telecommunication Union adopted provisions,  
 effective July 1, 1990, for the countries located in the Americas to  
 add ten AM band transmitting frequencies, from 1610 to 1700 kHz."

https://en.wikipedia.org/wiki/Radio_in_the_United_States

Re: Using a Signal Generator for an "In Home" radio transmitter
Think of PowerLine.


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Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/7/2019 11:33 AM, snipped-for-privacy@myshop.com wrote:
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Short answer: NO.
Longer answer:
Check the FCC regulations for what you're allowed to do on what  
frequencies.  Depending on where you live, you might get in trouble
if some harmonic landed on some emergency frequency.

Turn on the generator; tune the radio to that frequency;Is the unmodulated
signal absolutely quiet on your radio?
Let it sit for an hour; is the generator still on the same frequency
as the radio?
If you got this far, you might have a chance.

Re: Using a Signal Generator for an "In Home" radio transmitter
On Monday, January 7, 2019 at 11:34:24 AM UTC-8, snipped-for-privacy@myshop.com wrote:
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Well, yes, it's  possible.   But, it isn't necessary.   There are Bluetooth options
if your 'antique' radios can accept a bit of straightforward audio input.
A variety of MP3-compatible Bluetooth players (like, maybe in your  cellphone?)
can be found, with Bluetooth output, and receivers are a common item: some
inductive coupling to the audio signal channel could be easy to arrange.

If you can put an  induction coil in the vicinity of the radios, it doesn't
take much power to tickle an AM radio, with minimal AM interference
at longer distances.

Re: Using a Signal Generator for an "In Home" radio transmitter
On Monday, January 7, 2019 at 11:34:24 AM UTC-8, snipped-for-privacy@myshop.com wrote:
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This app note comes to mind:
<https://www.analog.com/media/en/technical-documentation/application-notes/an47fa.pdf>

note especially figure 116

Re: Using a Signal Generator for an "In Home" radio transmitter
On Mon, 07 Jan 2019 13:33:15 -0600, snipped-for-privacy@myshop.com wrote:

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All things are possible if you have enough time and money to throw at
the problem.

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In college, we threw together a radio station based on an AM carrier
current broadcast system.  The key to the system was the isolation
transformer between the transmitter output and the AC power line.  You
don't want 60 Hz going backwards into the transmitter causing hummmm
and you do want the frequency response of the transformer to include
the AM broadcast band.  That's not easy as there are a bunch of
compromises that need to be made.  Our first transformer literally
exploded when plugged in.  Our 2nd version did a little better by only
catching fire.  When we tried to measure the RF impedance of the power
line at 900KHz, we blew up the signal bridge.  

We eventually bought a commercial system after the fire marshal
decided that he would not tolerate an untested system.  I got lucky
and found an original data sheet:
<http://www.steampoweredradio.com/pdf/lpb/lpb%202-20%20am%20carrier%20current%20system.pdf
Note the T-8 power line interface.  On Page 6 it lists "Univ. State
Poly, College" (Cal Poly Pomona) which is where we built the system.

A tube type LPB carrier current transmitter:
<https://blogs.telosalliance.com/found-in-the-attic-february-2014

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Doesn't have enough RF power for carrier current.  It can probably be
heard somewhat all over the house, but will probably be noisy.

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Try 1650 KHz instead.  Kilocycles died 50 years ago.  

I wrongly assumed that you wanted to do it down the power lines using
a carrier current system.  Yes, an inside antenna MIGHT work.  I'm
fairly sure that your signal generator doesn't belch enough RF power
to be heard around the house without background noise.  I suppose it
would easy enough for you to try with your existing generator.

--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: Using a Signal Generator for an "In Home" radio transmitter
Jeff Liebermann wrote: "Try 1650 KHz instead.  Kilocycles died 50 years ago."


Any tech worth their salt understands both.  They  
express the same value.

Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/8/19 10:02 PM, snipped-for-privacy@gmail.com wrote:
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And only the humor impaired see the need to point that out.

--  
"I am a river to my people."
Jeff-1.0
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Re: Using a Signal Generator for an "In Home" radio transmitter
On Tue, 8 Jan 2019 20:02:30 -0800 (PST), snipped-for-privacy@gmail.com wrote:

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Bulk table salt sells for about $100 per metric ton.  Methinks I'm
worth more than that.

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Not the way they were originally written.  Hz = cycles/second.  
However, the original comment was "16,500 kc" which is just cycles. No
way to know if that's cycles/sec, cycles/minute, cycles/fortnight, or
just counting waveform cycles.  If he had written "cps", which means
cycles/second, I might agree, but not kc.  



--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: Using a Signal Generator for an "In Home" radio transmitter
snipped-for-privacy@cruzio.com says...
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But at least it was "k" for 1000x, not "K" for 1024x ...

Mike.

Re: Using a Signal Generator for an "In Home" radio transmitter
On Tuesday, January 8, 2019 at 11:02:34 PM UTC-5, snipped-for-privacy@gmail.com wrote:
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OK smartypants, what is -40 Fahrenheit in Centigrade ?  

Re: Using a Signal Generator for an "In Home" radio transmitter
On Wednesday, January 9, 2019 at 9:31:42 PM UTC-5, snipped-for-privacy@gmail.com wrote:
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The same. I am bi-temperate having lived under metric and non-metric systems.  

Peter Wieck
Melrose Park, PA  

Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/7/2019 1:33 PM, snipped-for-privacy@myshop.com wrote:
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  >so I can
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I do it the other way, I feed antique radio programs from my internet  
radio into my FM transmitter, so I can listen on my portable radio.

  Two of my favorite Old Time Radio Stations,

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Stoke up the fire and listen to,

Sherlock Holmes
Johnny Dollar
Philip Marlowe
Dragnet- Features Jack Webb and advertises Fatima cigarettes >  
https://archive.org/details/Dragnet_OTR/Dragnet_49-06-17_ep003_The_Werewolf.mp3Hall
of Fantasy
The Bob Hope Show
Have Gun Will Travel
Escape
Bold Venture with Humprey Bogart and Lauren Bacall
Tarzan
The Whistler
Richard Diamond
The Lives of Harry Lime  Orson Welles does the lead role
Broadway Is My Beat
Bob & Ray
Suspense
Box 13
Philo Vance
The Lone Ranger
Screen Director's Playhouse
The Six Shooter
Gunsmoke    ?William Conrad did the voice for Matt Dillion
Fort Laramie Raymond Burr does the lead role.
X Minus One

                         Mikek

Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/8/19 9:19 AM, amdx wrote:
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And how is that supposed to work with a bunch of AM radios?

--  
"I am a river to my people."
Jeff-1.0
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Re: Using a Signal Generator for an "In Home" radio transmitter
On Tuesday, January 8, 2019 at 11:09:38 AM UTC-5, Fox's Mercantile wrote:
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You feed the headphone jack of the FM radio into an AM XMTR...

Sheesh Jeff!!

Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/8/19 11:46 AM, John-Del wrote:
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Heh, I keep seeing people totally oblivious to the requirement
of an AM transmitter for BCB AM radios.

--  
"I am a river to my people."
Jeff-1.0
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Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/8/2019 12:22 PM, Fox's Mercantile wrote:
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  I was oblivious to your requirement, you made that clear. I just  
wanted to let people know what I do, and to make them aware of the old  
radio programs available over the internet. Listening to Dragnet as I  
write, on an FM radio!

                             Mikek

btw, has anyone tried a class E amplifier as an AM transmitter?
  Base/gate drive is transmit frequency, B+ is the audio.
I'll google it.


Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/8/19 6:10 PM, amdx wrote:
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On of the "Impress kids" kit is an AM transmitter.
It's 1 MHz TTL crystal oscillator.
The Vcc is fed through an audio transformer.

Pretty slick, an AM transmitter with only 2 parts.


--  
"I am a river to my people."
Jeff-1.0
We've slightly trimmed the long signature. Click to see the full one.

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