Ridiculous range on VHF?

[Brian Abraham]

Not VHF AM but military VHF FM around 50 MHz once picked up a signal from Puckapunyal in Victoria from Lancelin in WA. Low powered manpack radios.

While training with the Army at Pucka we were told of them receiving PRC-25 transmits from Vietnam during the hostilities. The PRC-25 operated in the high HF/low VHF frequency band using frequency modulation (FM), it had a maximum range, using full power and its standard antenna, of approximately 5mi/8km, depending on terrain conditions. Nominal transmit power was 1.5 to 2 watts but it commonly produced four.

Personally heard aircraft making taxi calls at Sale while seated in an office at Essendon.

Military aircraft use the ducting phenomena to avoid radar detection at times. Similar to subs avoiding sonar detection. A Navy ship nav reported radar painting New Zealand during exercises off the coast of Jervis Bay.

Radar Basics in particular page Radar Basics - Anomalous Propagation of Electromagnetic Waves

[ampclamp]

As an amateur radio operator I have experienced ranges of several hundreds of kilometres on the 2 metre band.
Most likely tropospheric ducting or less likely some sporadic E layer skip.

[Ozdork]

Back in last century (early 80's) I was a Shrike Coastwatch driver - I recall having a perfectly clear conversation with another CW Shrike - I was at 1000' in the circuit at Gove, while he was in the circuit over the other side of the Gulf at Weipa.

[YBMK Tower]

Heard Flydoc 30nm south east of YCKN whilst 10 west of YBMK at 1000agl on 126.7 this morning. Around 430nm between us.

[avconnection]

PAD app on Mel centre from ABA at 4000'. Just over 1000nm at the time. The irony of course was trying to cancel SAR on HF with no joy.

[Ex FSO GRIFFO]

Ah well, just to add one more....

Working away in KG FSU a couple of 'late afternoons' when aircraft 'EXN' or something called at 30 miles inbound.....

Now, I had nothing on any 'EX?"s at all, but I did know that in those days, the aircraft whose regos commenced with 'EX?" were usually 'Aero Commanders'....and while I was checking with Flight Data, MILDURA FSU answered, and gave the 'usual responses'....

So, I simply called Mildura on the 'common' VHF, 122.1, & and we agreed to ignore any callsigns that we knew were not 'ours'.

This situation lasted for about an hour or so, and then simply 'faded away'...

Happened a few times, but right now I cannot remember the time of the year.
'Amusing' and interesting at the time....
Cheers

Similarly, on more then a dozen occasions it would appear that KG FSU was the only unit able to hear aircraft at Moruya / Merimbula (?), S. NSW, apparently, on 8mhz HF calling SY for cancellation of SAR....5 x 5......at around 'evening time' KG.

Who do you call now...? 'Mum' on ya I-phone....

[MotCap]

As a young boy I spent many days riding in the car with my dad. He worked for the City of Chicago, Department of Electricity. His auto was equipped with a Motorola FM radio for dispatch to outages of intersection (stop & go) lights. It was fairly common to overhear broadcasts from another station in California, roughly 1,800 NM distant.

[1DC]

I was in the Merchant Navy in the sixties,sailing on oil tankers. When we entered the Persian Gulf bound for Ras Tannura (Saudi Arabia) for a period of about 30 minutes we could regularly contact Ras T. on VHF,a distance of about 300 miles. The contact was loud and clear but only for around the thirty minute period, a steaming distance of about 8 nautical miles. We then lost contact until the following day when we were about 25 miles away. The Sparks said it was the bounce of the radio waves.