There are cheap USB plugs that convert analog to digital (small USB sound cards)
There are also very inexpensive RTL-SDR USB receivers.
It is possible to run SDR software on smartphones. Loran technology is advancing.

In Italy band allocation changed however a PC can control a specific type of low power AM transmitter.
The PC takes the input and output of audio using software and interfaces transmitter it can have tightly spaced AM channels.
People like wide signal bandwidth for music because it sounds better with lots of content but ...
talk radio can be narrow 8 bit and many channels are possible.

Having said that, the original question,
Where can He find documentation on traditional AM Radio for builders?

A DIY Elenco Radio kit has all the documentation that was asked for along with all the parts and an extensive manual.
I think it would be easier to start over than to modify it in breakout board style.
There is always something that can be accomplished with it, who knows?

 

There are cheap USB plugs that convert analog to digital (small USB sound cards)
There are also very inexpensive RTL-SDR USB receivers.
It is possible to run SDR software on smartphones. Loran technology is advancing.

In Italy band allocation changed however a PC can control a low power AM transmitter having tightly spaced AM channels.
People like wide signal bandwidth for music for it's content but ...
talk radio can be narrow 8 bit and many channels are possible.

A DIY Elenco Radio kit has all the documentation that was asked for along with all the parts and extensive manual.
I think it would be easier to start over than to modify it in breakout board style.
There is always something that can be accomplished with it, who knows?

Thanks a lot - OK

 

I did not see it mentioned, but even if the frequency conversion works as hoped, you would still be feeding an FREQUENCY MODULATED signal into a receiver only built to receive AMPLITUDE MODULATED signals. So the reception would not be useful.
The (not at all simple) way to make it actually work has already been described in detail. Also a bunch of other ideas of other schemes.

 

I did not see it mentioned, but even if the frequency conversion works as hoped, you would still be feeding an FREQUENCY MODULATED signal into a receiver only built to receive AMPLITUDE MODULATED signals. So the reception would not be useful.
The (not at all simple) way to make it actually work has already been described in detail. Also a bunch of other ideas of other schemes.

I have already solved everything - thanks a lot - I have solved the problem- bye

 

I guess I don't understand the problem, you buy a cheap off the shelf AM radio tune it in to the station you want to listen to use the earphone Jack on the AM radio and feed it into an FM transmitter all of this hardware can be bought off the shelf as is with a minimum modification. What is it you need?

 

I guess I don't understand the problem, you buy a cheap off the shelf AM radio tune it in to the station you want to listen to use the earphone Jack on the AM radio and feed it into an FM transmitter all of this hardware can be bought off the shelf as is with a minimum modification. What is it you need?

He's done with this, the root need was a audio amplifier. The idea was for the old radio to be the amplifier. A much more logical solution as found and agreed on.

 

I guess I don't understand the problem, you buy a cheap off the shelf AM radio tune it in to the station you want to listen to use the earphone Jack on the AM radio and feed it into an FM transmitter all of this hardware can be bought off the shelf as is with a minimum modification. What is it you need?

I solved the problem like this, THANKS TO ALL OF YOU

 

**Project: FM-to-AM Converter Circuit – Need Complete, Functional Schematic (Like My AM-to-FM Version)**

Hello everyone, I am an old hobbyst 86 years old and excuse me for mistakes.....

I'm working on a project where I need to **convert FM signals (88–108 MHz) into AM signals (~1 MHz)** so that they can be received on a standard AM radio. I’ve already built an AM-to-FM converter using a single transistor oscillator, and now I want to create the reverse: an FM-to-AM converter.

### Goal:
- Receive a **standard FM radio station**
- Extract the **audio signal**
- **Modulate** that audio onto a **1 MHz AM carrier**
- Output it as a low-power AM signal receivable by an AM radio

---

### What I Want:

I need a **complete, working schematic** that:

- Is built using **real, discrete components** (no modules, no black boxes)
- Uses common parts like **BF494, 2N3904, NE612, LM565**, or similar
- Includes:
- FM tuning input stage (L1 + C1)
- FM demodulator (PLL or simple ratio detector)
- Audio amplifier (if needed)
- AM modulator (transistor-based)
- AM oscillator (~1 MHz, L2 + C3)
- Power supply (3V–9V)
- Antenna connections (FM in, AM out)

### ️ Components I’ve considered:

| Component | Value/Type | Purpose |
|-----------|------------|---------|
| Q1 | BF494 / 2N3904 | FM RF Amplifier |
| L1 | 5 turns (24 SWG, 5mm diameter) | FM tuning |
| L2 | 7 turns (24 SWG, 5mm diameter) | AM oscillator |
| C1 | 10pF | FM tuning |
| C2 | 0.01µF | Coupling |
| C3 | 22pF | AM frequency |
| R1 | 10K | Bias |
| R2 | 2.2K | Collector load |

---

### Usage:

- Tune C1 to choose the FM station.
- L2 + C3 set the AM output frequency (~1 MHz).
- AM output is a short antenna (10–30 cm wire) to be received by a nearby AM radio.

---

### Style:

I'd really appreciate if someone could provide a schematic **similar in layout to classic hand-drawn or educational diagrams** – something clean and simple like you'd see in textbooks.

---

Thanks in advance to anyone willing to help! This is for educational and experimental use, not for broadcasting or interference.

I suspect this is illegal, effectively transmitting on frequencies that you need to be licensed by the FCC.

 

I suspect this is illegal, effectively transmitting on frequencies that you need to be licensed by the FCC.

The OP was likely pushing ideas, not of his own. I don't think the FCC has jurisdiction where the OP lives.
https://www.google.com/maps/place/I...try=ttu&g_ep=EgoyMDI1MDQyMC4wIKXMDSoASAFQAw==

 

As far as I know the 10mw rule is still in effect. Anything in that power range is hard to enforce anyhow, because such low power is not likely to interfere with anyone or seen by the government.

 

As far as I know the 10mw rule is still in effect. Anything in that power range is hard to enforce anyhow, because such low power is not likely to interfere with anyone or seen by the government.

The rule is mainly about 'harmful' interference with a max power even if there is no 'harmful' interference. So even if the power level is 1 mw, if it causes 'harmful' interference, you must shut it down.
https://www.nsma.org/wp-content/uploads/2015/04/Defining-the-Harm-in-Harmful-Interference.pdf

Defining the Harm in Harmful Interference

https://www.fcc.gov/enforcement/areas/interference-resolution

The Enforcement Bureau, through its field offices, supports the Commission’s public safety goals, including by investigating and resolving radio frequency interference caused to public safety communications and critical infrastructure. Interference complaints come from a variety of sources, but the Bureau’s highest priority is responding to complaints from those that protect the public and preserve security (e.g., Federal Aviation Administration (FAA) air traffic control and navigation, U.S. Coast Guard search-and-rescue operators, Emergency Medical Service technicians, police, and firefighters). The Field Offices also investigate and resolve instances of harmful interference to or from commercial entities (e.g., wireless providers, broadcasters) and other sources.

 

The OP was likely pushing ideas, not of his own. I don't think the FCC has jurisdiction where the OP lives.
https://www.google.com/maps/place/Italy/@40.8038572,2.1272835,3502805m/data=!3m2!1e3!4b1!4m6!3m5!1s0x12d4fe82448dd203:0xe22cf55c24635e6f!8m2!3d41.87194!4d12.56738!16zL20vMDNyamo?entry=ttu&g_ep=EgoyMDI1MDQyMC4wIKXMDSoASAFQAw==

Wow, he should reach out locally, I'm sure he'll find plenty of help!

 

There are cheap USB plugs that convert analog to digital (small USB sound cards)
There are also very inexpensive RTL-SDR USB receivers.
It is possible to run SDR software on smartphones. Loran technology is advancing.

In Italy band allocation changed however a PC can control a specific type of low power AM transmitter.
The PC takes the input and output of audio using software and interfaces transmitter it can have tightly spaced AM channels.
People like wide signal bandwidth for music because it sounds better with lots of content but ...
talk radio can be narrow 8 bit and many channels are possible.

Having said that, the original question,
Where can He find documentation on traditional AM Radio for builders?

A DIY Elenco Radio kit has all the documentation that was asked for along with all the parts and an extensive manual.
I think it would be easier to start over than to modify it in breakout board style.
There is always something that can be accomplished with it, who knows?

I solved all my problem - Thanks everyone