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Using a Signal Generator for an "In Home" radio transmitter

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Guest

Mon Jan 07, 2019 8:45 pm   



Is it possible to use a Signal Generator for an "In Home" radio
transmitter?

I would like to make a small in the house AM radio transmitter, so I can
listen to my own music collection of MP3 music on my antique radios. I
know I can buy a transmitter for this use, but I am wondering if I can
use what I already have.

For example, I have an Eico 315 Signal Generator. It has an internal
400cps audio generator, but it also has the capability of inserting
another audio signal.

So, can I just take a MP3 player and run that into the signal generator,
and connect the sig gen to a piece of long wire strung inside my home to
transmit the signal? Is there enough power to transmit inside my own
home? I'd probably string 10 to 20 ft of wire along the edge of the
ceiling, or across curtain rods from window to window.

Of course I'd set the sig gen to an MW AM radio frequency, such as
16,500 kc.

Pat
Guest

Mon Jan 07, 2019 10:45 pm   



On Mon, 7 Jan 2019 12:56:59 -0800 (PST), "pfjw_at_aol.com"
<peterwieck33_at_gmail.com> wrote:

Quote:
On Monday, January 7, 2019 at 2:34:24 PM UTC-5, tub...@myshop.com wrote:
Is it possible to use a Signal Generator for an "In Home" radio
transmitter?



It is absolutely possible. And, the quality of the signal transmitted will be based on the quality of the generator. BUT:

Make sure your radiated power does not exceed FCC part 15 limits. Which, as I remember, is about 100 mw on the commercial AM band. Also, make sure you do not exceed
antenna 'developed length' - which is very roughly ten (10) feet. You will get better results if you trim your antenna to the target frequency. When I lived and worked in
Saudi, I covered 80 acres with an SSTRAN transmitter, using a based-loaded coil mounted about 10 meters above grade, and transmitting on 1380 AM.
Not so good on the stucco-on-mesh villas, so I converted to FM in short order, using a Ramsey FM100B (1-watt). That covered a radius of about 5 km in good stereo.

Look up the FCC Part 15 rules for Medium Band AM.

Peter Wieck
Melrose Park, PA


I'm not sure what you meant by "trim your antanna to the target
frequency". If you are talking about an antenna that is resonant at
AM broadcast band frequencies, that is not practical (or legal as you
correctly pointed out) for a home transmitter. One wavelength at 1600
kHz is 187 meters (over 600 feet).

Fox's Mercantile
Guest

Mon Jan 07, 2019 10:45 pm   



On 1/7/19 2:56 PM, pfjw_at_aol.com wrote:
Quote:
Not so good on the stucco-on-mesh villas, so I converted
to FM in short order, using a Ramsey FM100B (1-watt).


Which is all well and good, but old table AM radios don't do FM.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

Look165
Guest

Mon Jan 07, 2019 10:45 pm   



Think of PowerLine.

tubeguy_at_myshop.com a écrit le 07/01/2019 à 20:33 :
Quote:
Is it possible to use a Signal Generator for an "In Home" radio
transmitter?

I would like to make a small in the house AM radio transmitter, so I can
listen to my own music collection of MP3 music on my antique radios. I
know I can buy a transmitter for this use, but I am wondering if I can
use what I already have.

For example, I have an Eico 315 Signal Generator. It has an internal
400cps audio generator, but it also has the capability of inserting
another audio signal.

So, can I just take a MP3 player and run that into the signal generator,
and connect the sig gen to a piece of long wire strung inside my home to
transmit the signal? Is there enough power to transmit inside my own
home? I'd probably string 10 to 20 ft of wire along the edge of the
ceiling, or across curtain rods from window to window.

Of course I'd set the sig gen to an MW AM radio frequency, such as
16,500 kc.


Fox's Mercantile
Guest

Mon Jan 07, 2019 10:45 pm   



On 1/7/19 1:33 PM, tubeguy_at_myshop.com wrote:
Quote:
Is it possible to use a Signal Generator for an "In Home" radio
transmitter?


Yeah, but it'll sound like crap.
Because most of those old generators will only do about
30% modulation. And they're not exactly set up for any
kind of modulation bandwidth.

There's the SSTRAN 3000 which I use.
<http://www.sstran.com/>
Another option is the Talking House transmitter.
<https://www.ebay.com/itm/223314565635>

Or, you can roll your own.
<https://antiqueradio.org/transmitter.htm>

--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

pfjw@aol.com
Guest

Mon Jan 07, 2019 10:45 pm   



On Monday, January 7, 2019 at 2:34:24 PM UTC-5, tub...@myshop.com wrote:
Quote:
Is it possible to use a Signal Generator for an "In Home" radio
transmitter?



It is absolutely possible. And, the quality of the signal transmitted will be based on the quality of the generator. BUT:

Make sure your radiated power does not exceed FCC part 15 limits. Which, as I remember, is about 100 mw on the commercial AM band. Also, make sure you do not exceed antenna 'developed length' - which is very roughly ten (10) feet. You will get better results if you trim your antenna to the target frequency. When I lived and worked in Saudi, I covered 80 acres with an SSTRAN transmitter, using a based-loaded coil mounted about 10 meters above grade, and transmitting on 1380 AM. Not so good on the stucco-on-mesh villas, so I converted to FM in short order, using a Ramsey FM100B (1-watt). That covered a radius of about 5 km in good stereo.

Look up the FCC Part 15 rules for Medium Band AM.

Peter Wieck
Melrose Park, PA


Guest

Mon Jan 07, 2019 10:45 pm   



You're off by a factor of ten. You want up to 1,650 KHz. Actually it is so easy to build an oscillator like that and easy to amplitude modulate that might be a better option. Well unless you have nothing better to do with the generator.

Crystal controlled would be better because drift is not good. But then if you just leave it on all the time it will settle in and be stable enough.

Another thing is to keep the power down, you don't need problems with the FCC. They got a SWAT team, I shit you not. I am not sure what you can get away with, maybe 100mW or 500, something like that. A quick Google didn't yield a straight answer but I would say just make sure the signal doesn't leave the house.

I know it is absolutely illegal to use any of the FM band, that this when they come and treat you like you're running a meth lab. However there is so much noise on AM that they might never even suspect. You might be better running the "transmitting antenna" through wires to the desired locations. I fit leaves the house, even on your own property that might mean trouble. And we are talking feds here, that means your miracle worker lawyer is no good.

Pat
Guest

Mon Jan 07, 2019 10:45 pm   



On Mon, 07 Jan 2019 13:33:15 -0600, tubeguy_at_myshop.com wrote:

Quote:
Is it possible to use a Signal Generator for an "In Home" radio
transmitter?

I would like to make a small in the house AM radio transmitter, so I can
listen to my own music collection of MP3 music on my antique radios. I
know I can buy a transmitter for this use, but I am wondering if I can
use what I already have.

For example, I have an Eico 315 Signal Generator. It has an internal
400cps audio generator, but it also has the capability of inserting
another audio signal.

So, can I just take a MP3 player and run that into the signal generator,
and connect the sig gen to a piece of long wire strung inside my home to
transmit the signal? Is there enough power to transmit inside my own
home? I'd probably string 10 to 20 ft of wire along the edge of the
ceiling, or across curtain rods from window to window.

Of course I'd set the sig gen to an MW AM radio frequency, such as
16,500 kc.


Yes. Your signal generator can be used for that. I doubt you need
more than a foot or two of wire for the antenna. The frequency you
mentioned, however, isn't MW. It's short wave (which may possibly be
received on your antique radios in addition to MW). Perhaps it was
just a typo on your part, but the AM broadcast band is from 540 to
1700 kHz (formerly referred to as kc). 1600 to 1700 wasn't part of
the band until after any radio called antique was sold, so 540 to 1600
is what you want to use.

Have Fun,
Pat

Jeff Liebermann
Guest

Mon Jan 07, 2019 11:45 pm   



On Mon, 7 Jan 2019 15:06:24 -0600, Fox's Mercantile <jdangus_at_att.net>
wrote:

Quote:
On 1/7/19 2:56 PM, pfjw_at_aol.com wrote:
Not so good on the stucco-on-mesh villas, so I converted
to FM in short order, using a Ramsey FM100B (1-watt).

Which is all well and good, but old table AM radios don't do FM.


No problem:

"Cuthbert FM to AM Converter MKII"
<https://radiojayallen.com/cuthbert-fm-to-am-converter-mkii/>

This solves the problem for those who can't find anything worth
listening to on AM, but want to listen on an antique radio. So, they
listen to FM broadcast on the AM radio.

--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Mike
Guest

Tue Jan 08, 2019 12:45 am   



On 1/7/2019 11:33 AM, tubeguy_at_myshop.com wrote:
Quote:
Is it possible to use a Signal Generator for an "In Home" radio
transmitter?

I would like to make a small in the house AM radio transmitter, so I can
listen to my own music collection of MP3 music on my antique radios. I
know I can buy a transmitter for this use, but I am wondering if I can
use what I already have.

For example, I have an Eico 315 Signal Generator. It has an internal
400cps audio generator, but it also has the capability of inserting
another audio signal.

So, can I just take a MP3 player and run that into the signal generator,
and connect the sig gen to a piece of long wire strung inside my home to
transmit the signal? Is there enough power to transmit inside my own
home? I'd probably string 10 to 20 ft of wire along the edge of the
ceiling, or across curtain rods from window to window.

Of course I'd set the sig gen to an MW AM radio frequency, such as
16,500 kc.

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.

whit3rd
Guest

Tue Jan 08, 2019 1:45 am   



On Monday, January 7, 2019 at 11:34:24 AM UTC-8, tub...@myshop.com wrote:
Quote:
Is it possible to use a Signal Generator for an "In Home" radio
transmitter?


This app note comes to mind:
<https://www.analog.com/media/en/technical-documentation/application-notes/an47fa.pdf>

note especially figure 116

whit3rd
Guest

Tue Jan 08, 2019 1:45 am   



On Monday, January 7, 2019 at 11:34:24 AM UTC-8, tub...@myshop.com wrote:
Quote:
Is it possible to use a Signal Generator for an "In Home" radio
transmitter?

I would like to make a small in the house AM radio transmitter, so I can
listen to my own music collection of MP3 music on my antique radios.


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.

Roger Blake
Guest

Tue Jan 08, 2019 6:45 am   



On 2019-01-07, Fox's Mercantile <jdangus_at_att.net> wrote:
Quote:
Or, you can roll your own.
https://antiqueradio.org/transmitter.htm


Very cool! I actually have a tube AM transmitter that I built from
a Lafayette kit in 1970. Found a photo and description online:

http://boatanchorpix.x10host.com/LA23.htm

The design seems typically dangerous for the time, it's a wonder I managed
not to electrocute myself or blow up other equipment with this thing! It
would be interesting to try resurrecting it with some appropriate safety
modifications.

--
-----------------------------------------------------------------------------
Roger Blake (Posts from Google Groups killfiled due to excess spam.)

NSA sedition and treason -- http://www.DeathToNSAthugs.com
Don't talk to cops! -- http://www.DontTalkToCops.com
Badges don't grant extra rights -- http://www.CopBlock.org
-----------------------------------------------------------------------------

Jeff Liebermann
Guest

Tue Jan 08, 2019 8:45 am   



On Mon, 07 Jan 2019 13:33:15 -0600, tubeguy_at_myshop.com wrote:

Quote:
Is it possible to use a Signal Generator for an "In Home" radio
transmitter?


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

Quote:
I would like to make a small in the house AM radio transmitter, so I can
listen to my own music collection of MP3 music on my antique radios. I
know I can buy a transmitter for this use, but I am wondering if I can
use what I already have.


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>

Quote:
For example, I have an Eico 315 Signal Generator. It has an internal
400cps audio generator, but it also has the capability of inserting
another audio signal.


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

Quote:
So, can I just take a MP3 player and run that into the signal generator,
and connect the sig gen to a piece of long wire strung inside my home to
transmit the signal? Is there enough power to transmit inside my own
home? I'd probably string 10 to 20 ft of wire along the edge of the
ceiling, or across curtain rods from window to window.

Of course I'd set the sig gen to an MW AM radio frequency, such as
16,500 kc.


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 jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

John-Del
Guest

Tue Jan 08, 2019 3:45 pm   



On Tuesday, January 8, 2019 at 9:12:17 AM UTC-5, pf...@aol.com wrote:

Quote:

Eventually, I am would like to set up a small NTSC TV transmitter, as TVs are becoming a greater and greater presence at Kutztown. But, it is something I would never use at home.

Peter Wieck
Melrose Park, PA


Years ago, I used to feed my shop's cable box into a distribution amp to cover the several drops I had around my store, one of which I fed into an antenna. This would allow quick verification of TVs with just putting my finger on the antenna terminal of any TV. One day the cable co. shows up and said we had a huge leak and wanted to check for an open ground. I switched off the AB switch feeding the antenna and the problem was gone.

In any case, you can try feeding the RF output of any VCR or any RF modulator into a decent VHF amp and feed an antenna. Probably cover the area you need without spending any money.

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