The 11 Meter Broadcast Band 25.600 - 26.100 mHz Shortwave

[LBP]

According to an ACMA spectrum assignment search within the 11 meter
broadcast band 25.600 - 26.100 mHz
there is only one solitary assigned frequency in the whole of
Australia.

Frequency assigned 25.760 MHz, emission mode 6K00A2D, Transmitter
Power 3.50 pY, Location 2620 NSW.

So there's nothing there - this shortwave band is open spectrum real
estate and ideal for HF Domestic development.

If you have doubts - have a look for yourself - this is a recognised
shortwave broadcast band.

Band Frequency Range Remarks

120 m 2300 - 2495 kHz tropic band
90 m 3200 - 3400 kHz tropic band
75 m 3900 - 4000 kHz shared with the North American amateur radio
80m band
60 m 4750 - 5060 kHz tropic band
49 m 5900 - 6200 kHz
41 m 7200 - 7450 kHz shared with the amateur radio 40m band
31 m 9400 - 9900 kHz Currently most heavily used band
25 m 11,600 - 12,100 kHz
22 m 13,570 - 13,870 kHz substantially used only in Eurasia
19 m 15,100 - 15,800 kHz
16 m 17,480 - 17,900 kHz
15 m 18,900 - 19,020 kHz almost unused, could become a DRM band
13 m 21,450 - 21,850 kHz
11 m 25,600 - 26,100 kHz may be used for local DRM broadcasting

11m band – This band is seldom used. Day reception tends to be poor
when the solar cycle is low but potentially excellent when the solar
cycle (generally indicated by number of sun spots) is high. Night
reception is nonexistent except for local ground wave propagation.
Digital Radio Mondiale has proposed that this band be used for local
digital shortwave broadcasts and conducted an extensive test of the
concept in Mexico City in 2005.

More info: http://en.wikipedia.org/wiki/Shortwave_bands

[LBP]

Atec raised some interesting points in particular issues of noise,
interference and signal propagation on this band, which got me
thinking further..

I had a thought about areas/locations where there is a significant
risk of QRM or interference ..

Assignments could be made conditional much like the lower part of the
6 meter amateur band
50 - 52 mHz where if you're located within a certain distance of the
TV Channel 0 transmitters
you can't use that part of the spectrum.

Follow this link and scroll to the 6 metre band section:

http://www.wia.org.au/members/bandplans/data/documents/Australian%20Band%20Plans%20110515.pdf

snap shot of part of text:
No operation on any frequency below 52 MHz is permitted within 120 km
of main channel 0 stations, or within 60 km of translators which have
their outputs or inputs on channel 0.
No operation is permitted if it causes interference to reception of
Channel 0 television.

Also similar to how New Zealand has conditional use of certain
frequencies assigned to the Low Power FM broadcasters

Follow this link for explanation:
http://www.rsm.govt.nz/cms/licensees/types-of-licence/general-user-licences/low-power-fm-broadcasting

and scroll down to schedule 2.

Mind you, within the whole 11 metre broadcast band there is only one
actual frequency assignment - so all other inside Australia
emissions in this band are likely to be spurious and presumably
unintended.

I checked for any possible LIPD allocations for this band but the
answer is no -

http://www.comlaw.gov.au/Details/F2009C00545

There is a 1 watt EIRP LIPD allocation for the slightly higher 11
meter band 26.957–27.283 mHz
conditional as follows:

1. Separation of the operating frequency from the centre frequency of
any adjacent citizen band radio channel must be at least 5 kHz.
2. The emission bandwidth must not exceed 10 kHz.
3. Maximum EIRP 1 watt:

This topic of 11 metres is an interesting one and that's why I've
created this new thread as I think it deserves greater debate.

[atec77]

Post by LBP
No operation on any frequency below 52 MHz is permitted within 120 km
of main channel 0 stations, or within 60 km of translators which have

I think the rules will change shortly as with the dropping of vhf non
digital tv the risk of subsequent tvi is neglible , however imho based
on several decades of using 10/11m it's facility as a broadcast medium
is essentually nil in your context . The last cycle exaserbated
adjascent and same channel interfercne to the point where as a local
medium it was difficult at best to be heard over anything other than a
short distance or thousand of kilometers as x mentioned
Certainly most current radios fitted to motor cars and most homes
don't have a suitable tuning range which I think needs consideration ,
my preference is bottom of the band Fm and if and when this option
becomes viable I will be on air in seconds "(tested already) although 10
watts to the coax seems more reasonable as a begging to me with the
option of 50 watts a possibility
The hf bands should be positioned so rx on existing equipment is
possible so perhaps one end of the am broadcast band in a channel narow
band arrangement with resonably low power not exceeding say half the new
ham power of 1kw(being approved soon) of 500 watts am or sideband in a
short wave section slated for a later date , is there an area in the 70
or 60 metre available ?
Atm it's all guess work and conjecture but gettin hf at 500 watts is
dead simple and takes a phone call, fm is a low cost of ebay and a computer
Not a big ask is it ?
The real problem I see with all of this is over the last couple of
decades the lack of trained personal suggests anyone anting to take this
broadcasting lark on needs some training and a permit situation to gain
more power , but them maybe not just let it go open slather and fall
apart maybe ?

[vk3ye]

These frequencies are great for amazing results with low power or with weak
signal modes like SSB, but I can't see the attraction of it for serious
broadcasting use (where you need a. good reliabilty and b. freedom from
interference) for the following reasons:

1. Unlike 88-108 MHz receiving antennas are unweildy (3m long). And unlike
530 - 1600kHz ferrite rods are not an option. Magnetic loops are good but
are too directional for mobile use and have narrow bandwidth.

2. Higher noise, including clicks and pops from electrical equipment and
power lines than VHF

3. Summer sporadic-E - means frequencies can't be reliably reused between
Australian capital cities (which are spaced just right for sporadic-E)

4. Ionospheric propagation modes are too unreliable for regular
long-distance service, yet create interference when present. Whereas lower
frequencies have more reliable ionospheric propagation and higher
frequencies have less, making for reduced interference

The broadcasting frequency with most similar characteristics to 26 MHz are
our TV channel 0 and the 40 MHz or so used by the UK's 405 line system.
These frequencies have or are being phased out - due in part to the problems
above. And even CBers have largely abandoned 27 MHz in favour of UHF (though
the plum spectrum for mobile / handheld work is VHF high-band IMHO).

So it's spectrum that no one wants, and with good reason for commercial
applications.

[vk3ye]

Post by vk3ye
So it's spectrum that no one wants, and with good reason for commercial
applications.

I should add that 29 MHz FM is a very inferior mode. It's amazing for the 1%
of the time the band is open or if you're well within service area, but
there are many times when it's hissy and dropping out while SSB is readable
(but not great for broadcasting).

Same goes for 3 - 4 MHz AM due to phase distortion. I agree with what Dave
was saying last night - high quality SSB is far superior for evening work.

[LBP]

Post by vk3ye

Post by vk3ye
So it's spectrum that no one wants, and with good reason for commercial
applications.

I should add that 29 MHz FM is a very inferior mode. It's amazing for the 1%
of the time the band is open or if you're well within service area, but
there are many times when it's hissy and dropping out while SSB is readable
(but not great for broadcasting).
Same goes for 3 - 4 MHz AM due to phase distortion.  I agree with what Dave
was saying last night - high quality SSB is far superior for evening work.

Peter it's a shame you didn't get in very well last night - you should
skype in next time..

Next week the 160 may not be on till late because of contesting (I'll
probably be away next Saturday).

Interesting points made about 26 mHz - Personally I think the band
could be interesting even with
all the potential issues associated with it. The thing is, it's a
hardly used piece of spectrum, I don't think any of the International
broadcasters are using it - so it sits dormant and waiting for it's
day to arrive.

I have a feeling Minister Tatey is open to using this band for
broadcasting domestically - we'll see what his White Paper producers.

[www.format3.com.au | www.stationx.com.au]

Ok

Seems the few of us that have been CB heads have forgotten how
IMPOSSIBLE is was to talk across town when the skip was running. Then
there was the horrid skip distance where Sydney we would miss from the
Gold Coast and get everything else over 1000km away day or night. Your
broadcasting service doing that! Yeah right!?!?!

Plus I think 100 watts would only go 10km even with DRM on it. Don't
forget kiddies we are talking consumer grade radios not CB bases with
1/2 wave ground planes etc.

There is a point WHY the DRM people are trying the 26 mhz area and
it's more a technical thing I'm lead to beleive. The higher you go the
bigger the tune dip is in your aerial system. This means you are
radiating those sidebands more easily and DRM being a digital mode
needs the full bandwidth it can get. Don't forget it's more or less
seriously key full on 100% duty cycle. So a DRM TXer needs to be even
more beefy than an old AMer! But you win on the slippery dip what you
loose on the merry go round. The power needed to push the DRM signal
the same distance is less.

Seriously there is no way 26 mhz is the answer.

[atec77]

Post by vk3ye

Post by vk3ye
So it's spectrum that no one wants, and with good reason for commercial
applications.

I should add that 29 MHz FM is a very inferior mode. It's amazing for the 1%
of the time the band is open or if you're well within service area, but
there are many times when it's hissy and dropping out while SSB is readable
(but not great for broadcasting).

I have had over the last week contacts on fm into Asia and Zl
perhaps my wet string is larger than yours ?
First contact with Thailand for some time although 6m owuldn't make
the trip even on ssb

Post by vk3ye
Same goes for 3 - 4 MHz AM due to phase distortion. I agree with what Dave
was saying last night - high quality SSB is far superior for evening work.

7,.25 am seems ok , last night we chatted to Townsville , Gladstone
and Melbourne from Brisbane with ease
I don't have a decent stick for 80m so can't comment

[www.format3.com.au | www.stationx.com.au]

Post by vk3ye

Post by vk3ye
So it's spectrum that no one wants, and with good reason for commercial
applications.

I should add that 29 MHz FM is a very inferior mode. It's amazing for the 1%
of the time the band is open or if you're well within service area, but
there are many times when it's hissy and dropping out while SSB is readable
(but not great for broadcasting).

  I have had over the last week contacts on fm into Asia and Zl
  perhaps my wet string is larger than yours  ?
  First contact with Thailand for some time although 6m owuldn't make
the trip even on ssb

Post by vk3ye
Same goes for 3 - 4 MHz AM due to phase distortion.  I agree with what Dave
was saying last night - high quality SSB is far superior for evening work.

  7,.25 am seems ok , last night we chatted to Townsville , Gladstone
and Melbourne from Brisbane with ease
  I don't have a decent stick for 80m so can't comment
--
X-No-Archive: Yes

Do we really care Atec? I think you of all people would know what
issues broadcasting on this band would have to cop.

[atec77]

Post by www.format3.com.au | www.stationx.com.au

Post by atec77

Post by vk3ye

Post by vk3ye
So it's spectrum that no one wants, and with good reason for commercial
applications.

I should add that 29 MHz FM is a very inferior mode. It's amazing for the 1%
of the time the band is open or if you're well within service area, but
there are many times when it's hissy and dropping out while SSB is readable
(but not great for broadcasting).

I have had over the last week contacts on fm into Asia and Zl
perhaps my wet string is larger than yours ?
First contact with Thailand for some time although 6m owuldn't make
the trip even on ssb

Post by vk3ye
Same goes for 3 - 4 MHz AM due to phase distortion. I agree with what Dave
was saying last night - high quality SSB is far superior for evening work.

7,.25 am seems ok , last night we chatted to Townsville , Gladstone
and Melbourne from Brisbane with ease
I don't have a decent stick for 80m so can't comment
--
X-No-Archive: Yes

Do we really care Atec?

of course one would care unless ignorant
there is a direct correlation between amateur operators and the
broadcast experience
I think you of all people would know what

Post by www.format3.com.au | www.stationx.com.au
issues broadcasting on this band would have to cop.

in english please