another radio question. Receiving stations far, far away

For the record, I have picked up the following:

• Russia. On an ancient Panasonic Short Wave radio.
• Sydney radio, on a REALLY old HMV (leather covered, steel chassis) transistor radio, out near Grenfell, NSW.
• 2WS-FM down in Queanbeyan (near Canberra).

Radio Moscow - Russia Radio Austria Swiss Radio International Vatican Radio Radio Canada

ummm - lots more..

It's all to do with propagation - radio signals bouncing off the ionosphere and back to earth many hundreds or thousands of kilometres away. Different seasons and times of day produce different propagation characteristics across the radio frequency spectrum. Sun spot activity also affects propagation...

Look up propagation of radio signals and you will soon learn why it all happens, how to make the most of it, and even how to predict it to some extent!

But I'm talking AM receivers here. Aren't the stations you mention short wave?

"Kate Fights, I Cry"

The AM band ends at 1700 kHz - just where the short wave band begins.

As a long time resident of Sydney I can say that it is (or was) very possible to hear several AM band transmissions originating in New Zealand whenever suitable atmospheric conditions prevailed, late at night on a modest radio.

The suonds sheep bleating was unmistakable.

.......... Phil

From a place called Mt. Helena about 30km east of Perth I used to pick up Sydney, Adelaide, Queensland, numerous asian AM radio and on the odd occasion US and European commercial AM stations at night on my Toshiba multiband receiver. I also picked up on my old B/W portable TV GWN channel 3 (as it was then before it went statewide) from Bunbury about 300km away and also Channel 11 in Geraldton well over 500km away.

One particular night I picked up channel 0, QTV from Queensland for a few hours and it was quite watchable.

The TV was a B/W National portable transistorised model with a single VHF rotary tuner and using only the indoor antenna that was attached to the back of it. I can't really explain why this particular set picked these stations up because my parent's set in the lounge with the external antenna received nothing.

Ironically neither set received the local Perth stations very well because we were on the wrong side of a slight hill. I still have the portable TV...

Regards,

Clockmeister.

We had 2XX here in Canberra on 1,008 kHz, same as 2AD in Tasmania, and that could be heard in the background sometimes, since 2XX was only 300 watts. Now they have moved to FM, and a sport station with races is there, with zero fidelity, offering odds on chances of losing all yer dough.

I have often heard Queensland stations here, and it depends on ionosphere refelections etc, and I am at a loss to explainn further, but should you be able to erect a long enough antenna with a length ideal for the broadcast band, preferably with an L plan shape, then the two antenna signals can be phase adjusted to prefer the station you want.

It won't be hi-fi.

But the trouble is most stations are same old boring stuff you get from the city stations since they have networked them all.

For short wave, a rotating beam antenna like what the ham radio guys use is quite good but their beams favour 7, 14, 28, 56 MHz. So maybe you shouls tudy the old books about radio wave propagation and antennas; many books are devoted just to antennas.

If you have a non resonant long wire antenna just thrown over the roof and running in through a window to your set, then its wise to make a good earth for the set, since the antenna signal

needs a *circuit*, so electrons can move from antenna to ground and back

One can also use an inductor to earth, then a series tuning capacitor to the antenna, and take the radio signal from the inductor. The capacitor is then tuned so the antenna and cap and inductor make a resonant circuit and this often boosts the signal you want with others close by maybe 15 dB. Noise outside this band will be rejected.

MW and SW depends a lot on antennas. Ask any ham.

I have to help a ham operator lower one antenna and raise another tomorrow.

The beam we are taking down has 4 rods or 9 metres long each, quite a beast.

Radio interest was real big in the 1950s, when guys built all their own gear. Now they buy at DSE and plug and play, or they use a "virtual" receiver that appears on a PC screen so the maouse can be used to alter RF gain noise filtering, selectivity,

band filtering, side band, et all. This approach simply digitisers the RF input signal and counts what comes in, then a program is applied to decode the data.

The radio waves are still there but today's latest receivers are very different to what they were up to the age of the PC.

Still, I have several old 7 tube communications sets I'd like to restore

that an old ham left to me when he passed away a few years back.. They would have gone to the tip otherwise. They can still give pretty good performance, and its possible to add digital processing to clean up speach signals.

Nothing here may be of much interest to hi-fi folks but the old ham I knew was very interested in the lo-fi side of ham and talking to old mates in the UK as well as what he could get from his sound system.

To know more about radio, you have to read books and do experiments.

Patrick Turner

Its hard not to drift off topic to SW.

But there is a lot to learn about MW or the 550kHz to 1650 kHz band.

Patrick Turner.

Some evnins youse can 'ear Helun Clak speakin loud acruss the Tasmin, frum NZ Parlimint.

Evun the shiip are nervus around her.

Patrick Turner.

As I said:

It's all to do with propagation - radio signals bouncing off the ionosphere and back to earth many hundreds or thousands of kilometres away. Different seasons and times of day produce different propagation characteristics across the radio frequency spectrum. Sun spot activity also affects propagation...

Different frequencies are affected in various ways by the ionosphere, sunspot activity, season, etc. AM broadcast band is at the bottom end of what many call "shortwave" and the lowest Australian Amateur Radio band is at 1800kHz, just above the AM broadcast band.

The concept of propagation remains true whether we are talking about AM broadcast, LW (long wave - below the AM band) or SW (short wave - above the AM band). The only difference is how the actual frequencies behave under certain conditions....

In the very old days I used to regularly listen to JJ in out of Sydney on an old AM radio in my shed most nights in Melbourne. .. Francis Xavier Holden

On shortwave, you can hear stations from halfway around the planet. But I assume that you are asking about the 1MHz MW AM broadcast band. The farthest station I've picked up here in New Jersey (next to New York City) was about 1200 miles, or about 2 Megameters (2000km) distant. That's about halfway across the USA.

I used to have a set that would pick up 3/4 of the way around the planet...

Okay... But halfway around the planet from NJ puts you just off the western end of Australia. Every other point in the world is closer. ;-)

Point of confusion: Most broadcast MW and SW stations use amplitude modulation, aka AM. Though most people will think of the MW broadcast band when "AM radio" is mentioned. But strictly speaking, a SW radio that can hear an amplitude modulated SW broadcast is an "AM receiver".

More precisely the OP wanted to ask "How far away was the furthest MW broadcast radio station you have ever received?" For myself, I picked up a station in Iowa while listening in NJ. That's a bit less than 2000km. But remember that the USA's MW broadcast band is rather crowded, thus blotting out further distance reception. Many frequencies here you get small islands of service in a sea of interference.

"robert casey"

" Question is how far a signal have you ever received on a portable AM band radio. "

Shame how many folk do not read as carefully.

............. Phil

To state the bloody obvious. Americans...

Might be long path .wawawa

Short wave IS AM. I've received Australian radio stations here in England quite often. And generally about once a year we suffer co-channel interference on TV from South Africa.

Pearce Consulting

Just for PA . Seems very appropriate