Canadian hams gain new MF (620m) band

[W9JEF]

ARRL has p*t*tioned the FCC--could take a while--stay tuned.



The ARRL in 2012 petitioned (http://apps.fcc.gov/ecfs/document/view?id=7022073018)
the FCC to carve out the same band for US hams, but the Commission has not yet
acted on the League’s request. The ARRL-sponsored WD2XSH (http://500kc.com/) experimental operation in
that region of the spectrum continues, with Fritz Raab, W1FR, as the
coordinator. Other experimenters also operate there from time to time.

By international agreement, the maximum equivalent isotropically radiated
power (EIRP) of amateur stations using 472-479 kHz may not exceed 5
W (or 1 W EIRP in some locations). In the US and in Canada, the 472-479 kHz band
is part of the larger 435-495 kHz segment allocated on a primary basis to the
Maritime Mobile Service and on a secondary basis for government Aeronautical
Radionavigation.
.



http://www.arrl.org/news/view/canadian-radio-amateurs-gain-new-472-479-khz-band

[W5BRM]

***a* t* se* c***da ** ge***ng **w fre*ue*****. H*p* *e get **em t**

[WØTKX]

http://upload.wikimedia.org/wikipedia/en/a/a9/Asterix_and_the_Falling_Sky.png

[NQ6U]

A half-wave dipole for 620m would be 985 feet (300m) long.

[W9JEF]

A half-wave dipole for 620m would be 985 feet (300m) long.

And for a dipole to be up a quarter wave--almost 500 feet high.

A top-loaded vertical with lots of radials might work out better.

[kb2vxa]

There are variations on a theme, such as the umbrella and Marconi T. In any case, any antenna for LF is inefficient and requires considerable real estate, to be a Lowfer and still be heard you have to pump a LOT of watts into it to get the allowed IERP. I've used high power amps that operate at these frequencies and believe me, they're expensive. You can build one, but it'll still cost ya, and it won't have the protection that commercial amps used for testing applications have, one slip and you'll let the magic smoke out.

[W9JEF]

VXA's umbrella image is reminiscent of my 80 meter turnstile and 4-wire open feedline.
Up 48 feet at the apex, ends sloping down to 27-30 feet. Feeders tied together, it's an
umbrella vertical on 160, 80, and 40 (fed against many radials and the powerline neutral).


There are variations on a theme, such as the umbrella and Marconi T. In any case, any antenna for LF is inefficient and requires considerable real estate, to be a Lowfer and still be heard you have to pump a LOT of watts into it to get the allowed IERP. I've used high power amps that operate at these frequencies and believe me, they're expensive. You can build one, but it'll still cost ya, and it won't have the protection that commercial amps used for testing applications have, one slip and you'll let the magic smoke out.

The beauty of vacuum tubes is that they're very forgiving
of slip-ups. No magic smoke in there to let out.
Cost can be minimized through cannibalization of transformers
and other parts from old microwave ovens.

[kb2vxa]

Beauty of tubes yes, transformers are not so forgiving. Since it's essentially audio you'd need to wind a very well insulated toroid with many secondary taps to find and match what would essentially be an unknown impedance. That's where things get a bit tricky. I've heard of hams using high power solid state audio amps, transistors being current devices deliver maximum power into low impedance loads and don't complain about high impedance, just deliver less power, or no power into an open circuit. Tubes being voltage devices, pretty much the opposite, put the output transformer at risk of breakdown if the load isn't properly matched. But you knew that, didn't you? You might want to ask the Lowfers what they use, they have plenty of experience I'm sure they're willing to share.

[W9JEF]

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I notice that the latest MFJ Antenna Analyzer now covers as far down as 530 KHz.
Missed it by THAT MUCH (apologies to Don Adams). Maybe with some tweaking,
it could be extended down to 492, but would likely void the warranty.

Back in 1957, I was mobile on 75, so low-Z antenna loading is no big deal.
I'm thinking four 811-A's in parallel push-pull with link-coupled output.
Big loading coil wound with that 1/4 inch silver tape from a hobby shop.

[koØm]

Clean up time.


.

[VE7DCW]

ARRL has p*t*tioned the FCC--could take a while--stay tuned.




http://www.arrl.org/news/view/canadian-radio-amateurs-gain-new-472-479-khz-band

Yup..... we got this sliver of an allocation on a secondary basis,but it's going to be quite awhile before I even think of experimenting with it......but I'll give credit to RAC who lobbied hard to get it approved at WRC-12 .....

The experimental licenses Industry Canada issued to help prove this band section was also helpful...... :yes:

[W7XF]

Yup..... we got this sliver of an allocation on a secondary basis,but it's going to be quite awhile before I even think of experimenting with it......but I'll give credit to RAC who lobbied hard to get it approved at WRC-12 .....

The experimental licenses Industry Canada issued to help prove this band section was also helpful...... :yes:

Petition Industry Can-a-duh to issue KØØky the FrØØtcake a restricted licence so that he can transmit only on that band.... :werd:

[kb2vxa]

When a maritime service complains to IC maybe they'll do something about him? Just MAYBE?

[PA5COR]

We have the 2000 meter band, 137.5 KHz to 137 KHZ
http://www.veron.nl/vereniging/download/algemeen_hf_bandplan-2013.pdf
And the 600 meterband 472 to 479 KHz.
And the standard bands as in the linky.

[W9JEF]

.



I've copied the experimental stations and airport beacons
using my 540 foot wire Beverage (up 6 feet, unterminated).
With the turnstile in umbrella vertical mode, all I get is noise.
Can't wait to see if it transmits effectively enough for a QSO.

[n2ize]

http://upload.wikimedia.org/wikipedia/commons/thumb/c/cb/RBG-LED.jpg/220px-RBG-LED.jpg

[ad4mg]

http://upload.wikimedia.org/wikipedia/commons/thumb/c/cb/RBG-LED.jpg/220px-RBG-LED.jpg

This is a technical discussion forum. There will be NO trolling in any of these types of forums.

That is the only warning that will be given regarding this.

[K0RGR]

We have the 2000 meter band, 137.5 KHz to 137 KHZ
http://www.veron.nl/vereniging/download/algemeen_hf_bandplan-2013.pdf
And the 600 meterband 472 to 479 KHz.
And the standard bands as in the linky.

Please keep that hidden! Too many U.S. hams want to divide our bands up with dedicated digital bands, and that will give them ideas!

[kb2vxa]

Too late, the cat was out of the bag over a century ago when digital was the ONLY mode.

[W9JEF]

Too late, the cat was out of the bag over a century ago when digital was the ONLY mode.

No reason for remorse. ;)

[KC2UGV]

Please keep that hidden! Too many U.S. hams want to divide our bands up with dedicated digital bands, and that will give them ideas!

Meh, we already have one: 30M