G-7000 FM/AM tuner board

I took my cover off today to look around and I noticed this switch on my FM/AM tuner board. What does it do?



On a slightly related question: I noticed there is a single connection point for an external AM antenna on the rear panel next to the FM antenna connections. Looking on the inside, it looks like this lead connects to a green wire, via a resistor, to the ferrite bar antenna. I've noticed that I do not pull very many AM stations and the few that I do manage to receive, only register up to 2 or 3 on the signal strength meter. What can I do to improve AM signal strength? The tuner was cleaned and re-aligned by a professional audio lab.

Found out it's a de emphasis switch. I'm still interested in improving my AM reception though.

For better AM reception you need a long, high, wire antenna, the longer and the higher it is the better. :thmbsp:

What kind of lengths are we talking?

I would say 50 feet would be a good starting place.

And a good RF ground is never a bad idea.

Tunable loop antennas can work quite well, They are directional and can be used to peak the signal of interest and or null unwanted signals and noise. And they can be placed away from local sources of unwanted signals and electrical noise.


Plans for them abound on the internet.

They can be kind of a fun, not to complicated little project that will work rather well. In general, due to an effect called capture area, the larger the loop antenna the better it will work.

There are even some commercially available tunable loop antennas that work okay.

Zenith understood the value of a good antenna for use with their Trans-Oceanic radios when a long wire antenna was not available. They had a loop antenna that they called the Wave Magnet antenna.

One thing to look at is keeping the antenna, what every form it takes, as far away from local sources of electrical noise as possible.

To be clear there is no substitute for full size outdoor antennas that are installed high and in the clear and used with a good RF ground.

For any antenna that is installed outside, one should observe proper grounding techniques.

What if I'm limited to an indoor antenna? An outdoor antenna won't fly where I'm living. I pretty much live in a room. (Fresh college grad still living with mom).

Any takers? I've hooked up a 50 foot length of insulated wire coiled in a triangular loop and I haven't noticed a difference at all.

More information or a picture of your loop will help.

In general unless one is building a tuned loop antenna, see picture below, keeping the wire as high an straight as possible will work better than forming it into a coil or loop.

See the link and picture below from the internet.

In the picture below, C1 is a variable capacitor that us used to adjust the loop antenna to the same frequency as the station that you are trying to receive. You might call it part of the magic that makes a loop antenna work.

When it comes to loop antennas in this context there are two types, one the responds to the electric field of the radio signal (those are the ones made up of several turns of wire as seen in the beginning of the link above) and loops that respond to the magnetic field of the AM signal.

This type of loop antenna is less susceptible to unwanted electrical noise, but may need an RF preamp.

There are some commercially available tuneable AM broadcast band antennas.

If you can get a loop antenna next to a window and as far away from anything that might create electrical noise, it may help.

I did some experimenting, I currently have the antenna draped around the perimeter of my room. I measured it out, it's more like 30 ft long...oops. Anyways, it seems to have made a small difference.

I assume "signal" is connected to the AM antenna connection on the back of the receiver and "ground" would go to the chassis ground? Sorry, I'm a newbie on working with AM antennas, so I don't mean to come off a bit dense. lol

Haven't AM transmissions stopped? Back in 2010............

Not in the USA, still plenty of stations, great programming, maybe not so much.

FM reception is good though. I'm barely pulling stations as far as 100 miles away. To be exact, I'm listening to WSFL in New Bern, NC from Virginia Beach, VA with a signal strength of 2.5/5 on the signal meter.

For my wire AM antenna, should I strip the insulation off of it?

Mgino757 said:

FM reception is good though. I'm barely pulling stations as far as 100 miles away. To be exact, I'm listening to WSFL in New Bern, NC from Virginia Beach, VA with a signal strength of 2.5/5 on the signal meter.

For my wire AM antenna, should I strip the insulation off of it?

Click to expand...

No need to, except for connection to the tuner of course.

Hyperion said:

No need to, except for connection to the tuner of course.

Click to expand...

Cool :thmbsp:

I guess I just need to buck up and build a legit antenna instead of messing around with using a wire as a makeshift antenna...or just stick to FM DXing instead since there's hardly anything worthwhile on AM anymore. I'm just perplexed that I'm pulling FM farther away than AM. Granted, I am using a legit dipole for FM.