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

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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.


Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/7/19 1:33 PM, snipped-for-privacy@myshop.com wrote:
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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
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Re: Using a Signal Generator for an "In Home" radio transmitter
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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.)

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Re: Using a Signal Generator for an "In Home" radio transmitter
wrote:

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I watched a youtube video about this transmitter (actually SSTRAN 5000).
I thought this was a good option. I clicked on the URL you posted and it
appears they are OUT OF BUSINESS. Their website says something to the
extent "No new orders after November xx 2017, and new customers who
already paid, will be issued a refund.......

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This one is being considered........
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Obtaining the inductors (coils) is that hard part for ANY transmitters.  
I recall haveing a tough time getting them in the late 1960s. I'm sure
it's 1000 times harder now. I did get the coils and did build what was
called a "Phono Transmitter" in the late 60's. It worked well. Then I
took it one step further. I replaced the tube with the horizontal output
tube from a TV, and upped the high voltage to around 800V. (The power
supply was on a separate chassis).  

At that time, I was living in a big city. Using a car radio antenna
mounted about 30 ft up on a tree, I put this thing on the air. I never
expected the results I got. Several neighbors said their AM radios could
not get any stations, except mine. A friend who lives in the suburbs
about 15 miles away, said he got my station, clear as a bell.  

I got carried away and had it running about 12 hours a day. Had friends
act as disk jockeys and we played a lot of the songs that were banned on
the regular radio stations. We got a regular studio sound mixer and
connected 3 turntables, an 8track and a reel to reel tape player, plus a
few microphones. A lot of people loved the station, and wanted to know
the location. But we never told that to anyone, knowing this was a
pirate station and not legal.  

One day a fancy car with all kinds of weird antennas on it began
circling my block. I shut off the transmitter immediately. I am very
sure it was the FCC, but that tree antenna was well hidden. I planned to
move it to another friend's house, but we never did go back on the air.  
I wish I still had that transmitter. If I did, I'd down power it back to
the original design.....

By the way, that thing taught me to respect electricity. I was probably
17 years old. I was tweaking the transmitter when I grabbed the plastic
knob on the tuning cap, but my knuckle touched the cap itself, which was
live 800VDC. I had a grounded microphone in my other hand. I was sitting
on a heavy oak chair. Both myself and the chair were thrown about 12
feet away. The guy who was with me, said I walked around in a daze for a
half hour and kept drinking water every few seconds. All I recall, is
what looked like a bolt of lightning, when it hit me, and laying on the
floor 12 ft from my bench. He said the microphone hit him in the head
when I "launched". I sort of recall shutting off the switch that powered
my whole bench, right after. That was one scary shock. The worse I ever
got.  

I did encapsule that tuning cap in a box after that, and modified that
cap as well, because I used to get arcing between the plates. The
original one was a common 365pf AM radio tuning cap. I remember buying a
costly ceramic cap to replace it. Then building a shield around it to
avoid any chance of touching it.

When I look back, that whole thing was a lot of fun, aside from that
shock. A lot of people were saddened when we went off the air.  


Re: Using a Signal Generator for an "In Home" radio transmitter
I keep a 3000 and a 5000, and for years I distributed them at Kutztown for  
Phil Bolyn, the developer. In my opinion, they are the ne plus ultra of ama
teur hobby AM transmitters. I will state for the record, that most (not all
) of the stuff you will find on eBay is either junk, too powereful, or too  
weak to be useful.  

http://www.talkinghouse.com/

These are often sold at Kutzown, already adapted for a stereo input. They h
ave the virtue of being frequency agile, and rather simple to operate, but  
as-furnished, they do not allow for much signal processing. Their more expe
nsive version does allow for such signal processing, as well as a considera
bly extended dynamic range. It is all in accordance with what you wish to a
chieve. Considering that back in the day, those transmitters were capable o
f broadcasting across the full audio band, but given the need to carry, and
 not step on adjacent frequencies, they pretty much limited the bandwidth t
o ~100 - ~5000 hz, often considerably less both ways. Whereas the receiving
 radios were capable of getting the entire audio bandwidth.  

Note that the SSTRAN is rated at 20-20K, and after using it, other transmit
ters will sound quite thin.  

Peter Wieck
Melrose Park, PA

Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/10/19 7:51 AM, snipped-for-privacy@aol.com wrote:
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As a friend of mine's brother in law so appropriately put it,
"Pay shit, get shit."


--  
"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 Monday, January 7, 2019 at 2:34:24 PM UTC-5, snipped-for-privacy@myshop.com wrote:
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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 fr
equency. When I lived and worked in Saudi, I covered 80 acres with an SSTRA
N transmitter, using a based-loaded coil mounted about 10 meters above grad
e, and transmitting on 1380 AM. Not so good on the stucco-on-mesh villas, s
o I converted to FM in short order, using a Ramsey FM100B (1-watt). That co
vered 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

Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/7/19 2:56 PM, snipped-for-privacy@aol.com wrote:
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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
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Re: Using a Signal Generator for an "In Home" radio transmitter
wrote:

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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     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
On Mon, 7 Jan 2019 12:56:59 -0800 (PST), " snipped-for-privacy@aol.com"

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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).  

Re: Using a Signal Generator for an "In Home" radio transmitter
On Monday, January 7, 2019 at 4:13:43 PM UTC-5, Pat wrote:

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http://www.sstran.com/pages/sstran_buildant.html

Go to the section on "tuning".  

Peter Wieck
Melrose Park, PA  

Re: Using a Signal Generator for an "In Home" radio transmitter
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 m
ight 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 y
ou 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 F
CC. They got a SWAT team, I shit you not. I am not sure what you can get aw
ay with, maybe 100mW or 500, something like that. A quick Google didn't yie
ld a straight answer but I would say just make sure the signal doesn't leav
e the house.  

I know it is absolutely illegal to use any of the FM band, that this when t
hey 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 ru
nning the "transmitting antenna" through wires to the desired locations. I  
fit leaves the house, even on your own property that might mean trouble. An
d we are talking feds here, that means your miracle worker lawyer is no goo
d.

Re: Using a Signal Generator for an "In Home" radio transmitter
On Monday, January 7, 2019 at 3:57:50 PM UTC-5, snipped-for-privacy@gmail.com wrote:

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 they come and treat you like you're running a meth lab. However there is s
o 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 g
ood.

No. There are multiple FM & FM stereo Part-15 compliant transmitters. Typic
ally, they are around 25 MW or so, and with a good antenna mounted high eno
ugh will easily cover a few acres.

https://sourcefmtransmitter.com/wp-content/uploads/2017/07/ramsey-fm100b-la
rge.jpg  

I keep this one, and it gets its heaviest use at Kutztown twice per year, c
overing both pavilions, and then some. Matched to this antenna:

http://img0016.psstatic.com/152423604_amazoncom-tru-match-fm-broadcast-ante
nna-kit---25-watts-.jpg      

There are (at least) half-a-dozen more options.  

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

Peter Wieck
Melrose Park, PA  


Re: Using a Signal Generator for an "In Home" radio transmitter
On Tuesday, January 8, 2019 at 9:12:17 AM UTC-5, snipped-for-privacy@aol.com wrote:

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 are becoming a greater and greater presence at Kutztown. But, it is someth
ing I would never use at home.  
Quoted text here. Click to load it

Years ago, I used to feed my shop's cable box into a distribution amp to co
ver the several drops I had around my store, one of which I fed into an ant
enna.  This would allow quick verification of TVs with just putting my fing
er on the antenna terminal of any TV.  One day the cable co. shows up and s
aid 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 modulat
or into a decent VHF amp and feed an antenna.  Probably cover the area you  
need without spending any money.

Re: Using a Signal Generator for an "In Home" radio transmitter
On Mon, 7 Jan 2019 12:57:48 -0800 (PST), snipped-for-privacy@gmail.com wrote:

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I used to live in a city with   50,000 residents in the southern U.S..
There was, and probably still is, a pirate station in the educational
FM band. It has been on the air for years and it doesn't interfere
with local FM signals.  I have sinced moved to a town of 20,000 people
in southern MN. Someone started a pirate station playing Tejano music
24 hours a day. Unfortunately their frequency was at 90.3 MHz and the
signal bled over onto the local MPR signal at 90.1. I complained to
the FCC and within 3 weeks they shut the station down. So it appears
that the FCC is more aggressive when the station impinges on
legitimate signals.

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

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"Harmful interference" vs. "unauthorized operation".  Both can come
with big fines... but, yes, the FCC is somewhat more likely to react
when faced with a situation where a legitimate licensed broadcaster is
being interfered with.  (Commercial licensees have paid $$ for their
licenses, and don't like losing market-share/coverage to pirate
transmitters).



Re: Using a Signal Generator for an "In Home" radio transmitter
On Tue, 8 Jan 2019 10:37:40 -0800, snipped-for-privacy@coop.radagast.org (Dave Platt)
wrote:

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Right now is probably the PERFECT time to operate a pirate station.
Since the government is shut down, the FCC is probably not doing much.
NO, I am not encouraging this, just commenting......


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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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
  

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

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Thanks to all who replied. I am considering geting one of them ebay mini
transmitters, but this is more to see if I can do it with the signal
gen. And I have 3 of them to try. I think my Eico 315 is the most
suitable though and is my best one.  

Yea, I was not thinking when I typed that band number. I was thinking
1650 khz though. (just to avoid other stations from interfering). I have
never known any AM stations to exist above 1600. I sort of thought all
radios went to 1700, but I guess I was wrong.

Just curious, in what year did they add 1600 to 1700 to the AM band?
It does seem to me that a few times I have sent a signal to one of these
antique radios and gone above 1600 though, while aligning them. But I
suppose it depends on the radio design and how far the tuning cap can
go.

For sound quality and for stereo, a FM transmitter would be better, but
most of my antique radios are only AM band.

I am not too worried about the FCC coming to "get me". First off, I live
in a all metal home. Metal siding and roof. To use my cellphone I have
to go outside. Secondly, I live on a farm, and the nearest neighbor is a
mile away. So even if it does leak outside a little, only the deer and
pesky raccoons who carry pocket radios will pick up my signal. Of course
I will take a walk with a pocket radio or use my car radio just to see
if it is going beyond my home, and how far.

Interestingly enough, after I posted this, I went to youtube and typed
in a few words to search for this. I found that I am not the first
person to attempt this. Some guy did it. He found that running a MP3
player right into the signal generator had very weak audio. He then ran
the MP3 player into a stereo amp, and connected the amp's output to the
signal gen. Doing that, did make a strong signal, but it was rather
distorted. However, he connected the 8 ohm speaker output to the signal
gen. That alone seems like an overload. I'd be more inclined to use a
preamp between the signal gen and the MP3 player. Or use the "tape out"
jack from on a stereo amp or receiver. (which is preamp output).

I'll play with it, and see what happens, and post the results, unless
the FCC hauls me away and locks me up in some prison in Russia.
(Which means I better not play any Russian music over the air).  :)


Re: Using a Signal Generator for an "In Home" radio transmitter
On 1/9/19 8:03 PM, snipped-for-privacy@myshop.com wrote:
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It is currently 530-1700 KHz.
Originally, in 1923, it was 540-1340 KHz.


--  
"I am a river to my people."
Jeff-1.0
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