Hi
The tuning screw for the W1GHZ boards is almost on the PCB for 2400MHz (with low side LO at 2256MHz). I'm not sure if they'd go down another 100MHz. I'll give it a try when I get a chance.
73
Iain
That 13cm issue
Re: That 13cm issue
73
Iain Crawford - VK5ZD
Munno Para West, SA - PF95ih
Iain Crawford - VK5ZD
Munno Para West, SA - PF95ih
Re: That 13cm issue
Matt and everyone else interested,
There is much more to this question. Some points to consider:
1. There is the issue of spillover of the wireless LAN and other devices located above 2404 MHz.
2. We need also to consider the Amateur Satellite allocations, but by staying aware of the packages that are in use at any time with OSCARs, it may be possible to coexist and for more people to operate terrestrial in the lower segment closer to 2400.
3. The EME operators have adopted the lower segment at 2300-2302, primarily because (flame suit on) the Americans appear to unwilling to transmit and listen in the other segments unless they are really serious (just my interpretation of what I have been reading over the past couple of years).
Point 3 conveniently fits in with the problem identified in point 1.
There are other options.
One option has been used by many on EME, as evidenced by the VK3NX website: http://www.vk3nx.com/X-BAND2300.html
There are others showing various schemes to achieve similar outcomes, including a European station (cannot recall the call at present) using a transverter with an Apollo32 LO to a mixer, with switched filters according to the desired band segment/s to be used on Tx and Rx.
All of this is fine for EME, where there are several main "centres of activity": VK just below 2302, US at 2304, Europe at 2320, possibly VK somewhere 2400-2404, ZL and JA at 2424.
Yes, it is a mess!
Just to complicate everything for terrestrial activity in VK, we have Advanced able to access 2300-2302, and both Standard and Advanced having access to the band segment starting at 2400.
In my view, IF we Advanced licensee move to 2300-2302, that may make contacts easier..... BUT we lose the chance to work any Standard licensees, who are restricted to above 2400.....
Would not a better approach for Advanced licensees be for us to build flexible transverters, so that we can operate at more than one band segment? And, of course, be prepared to look & operate on the higher segment....
Surely one of our aims should be to be increase amateur microwave activity.
Technically, the Apollo32 LO board makes flexible operation easier. Combine one (with the appropriate switching arrangements) with a mixer and switched filters will provide flexibility. Most PAs and LNAs will cover both band segments, but one may need to consider input filtering depending upon local WLAN and other ISM activity... just another challenge. The filter switching can be reasonably cheap, if one looks carefully on various web sites and/or at hamfests for multipole SMA relays, or you are willing to use the RF switch kits from VK5EME.
Graham VK3XDK had some interesting transverter designs on show at GippsTech, including a 2400 design. Or you could take a building block approach. Or look at other designs. It need not be super expensive.
All Advanced licensees moving to operate only on 2300-2302 will take us backwards overall, in my opinion.
Peter VK3PF
There is much more to this question. Some points to consider:
1. There is the issue of spillover of the wireless LAN and other devices located above 2404 MHz.
2. We need also to consider the Amateur Satellite allocations, but by staying aware of the packages that are in use at any time with OSCARs, it may be possible to coexist and for more people to operate terrestrial in the lower segment closer to 2400.
3. The EME operators have adopted the lower segment at 2300-2302, primarily because (flame suit on) the Americans appear to unwilling to transmit and listen in the other segments unless they are really serious (just my interpretation of what I have been reading over the past couple of years).
Point 3 conveniently fits in with the problem identified in point 1.
There are other options.
One option has been used by many on EME, as evidenced by the VK3NX website: http://www.vk3nx.com/X-BAND2300.html
There are others showing various schemes to achieve similar outcomes, including a European station (cannot recall the call at present) using a transverter with an Apollo32 LO to a mixer, with switched filters according to the desired band segment/s to be used on Tx and Rx.
All of this is fine for EME, where there are several main "centres of activity": VK just below 2302, US at 2304, Europe at 2320, possibly VK somewhere 2400-2404, ZL and JA at 2424.
Yes, it is a mess!
Just to complicate everything for terrestrial activity in VK, we have Advanced able to access 2300-2302, and both Standard and Advanced having access to the band segment starting at 2400.
In my view, IF we Advanced licensee move to 2300-2302, that may make contacts easier..... BUT we lose the chance to work any Standard licensees, who are restricted to above 2400.....
Would not a better approach for Advanced licensees be for us to build flexible transverters, so that we can operate at more than one band segment? And, of course, be prepared to look & operate on the higher segment....
Surely one of our aims should be to be increase amateur microwave activity.
Technically, the Apollo32 LO board makes flexible operation easier. Combine one (with the appropriate switching arrangements) with a mixer and switched filters will provide flexibility. Most PAs and LNAs will cover both band segments, but one may need to consider input filtering depending upon local WLAN and other ISM activity... just another challenge. The filter switching can be reasonably cheap, if one looks carefully on various web sites and/or at hamfests for multipole SMA relays, or you are willing to use the RF switch kits from VK5EME.
Graham VK3XDK had some interesting transverter designs on show at GippsTech, including a 2400 design. Or you could take a building block approach. Or look at other designs. It need not be super expensive.
All Advanced licensees moving to operate only on 2300-2302 will take us backwards overall, in my opinion.
Peter VK3PF
-
VK3MY
Re: That 13cm issue
Honestly, I can't see a issue being on 2403.100, yes i hear all the crap, not only from my own wireless network and cordless phones, but from everything else around the area and further abound, I have brilliant success on this band even with all the crud that is around
Radio is a IC-970H with 2/70/23/13cm, no pre amp, grid antenna at 65ft and 1W, fed with LDF-550 cable, my location is 168m asl with a clear shot from ssw around to short path U.S. through west, it is out of the question for me to go below 2400.00 as the radio doesn't go that low, and i won't be changing it till it dies, or I do.
I have plugged the grid antenna into my PC and it is amazing just what I can pick up, wireless networks from over a km away.
My question is, why is everybody having such issues ? If I'm not having any problems in this location with heaps of crap, why is everybody else, why move, there is no need as far as my situation is concerned.
Ross
Radio is a IC-970H with 2/70/23/13cm, no pre amp, grid antenna at 65ft and 1W, fed with LDF-550 cable, my location is 168m asl with a clear shot from ssw around to short path U.S. through west, it is out of the question for me to go below 2400.00 as the radio doesn't go that low, and i won't be changing it till it dies, or I do.
I have plugged the grid antenna into my PC and it is amazing just what I can pick up, wireless networks from over a km away.
My question is, why is everybody having such issues ? If I'm not having any problems in this location with heaps of crap, why is everybody else, why move, there is no need as far as my situation is concerned.
Ross
Re: That 13cm issue
Hi Justin and Ross,
Sounds like at least some support for encouraging more activity at 2.4......
As far as I am aware, there is only one OSCAR up at present using S band. Operations at 2400.1 on narrowband modes should not cause issues with satellite Rx, unless you have a close neighbour on the satellites.
Given that Standards can operate above 2400, all the more reason to encourage more activity.
Peter VK3PF
Sounds like at least some support for encouraging more activity at 2.4......
As far as I am aware, there is only one OSCAR up at present using S band. Operations at 2400.1 on narrowband modes should not cause issues with satellite Rx, unless you have a close neighbour on the satellites.
Given that Standards can operate above 2400, all the more reason to encourage more activity.
Peter VK3PF
Re: That 13cm issue
Hi,
Whilst agreeing with Ross 3MY that the status quo should prevail for all the reasons mentioned, has anybody asked Mark 5EME whether the modifications required could be easily made to his transverter board?
The transverter 5 section hairpin filter is already specified for 2350 to 2450 Mhz, so I would have thought it a simple matter to add (snowflake) the requisite 1mm or so to each of the hairpins to bring the filter down the 50 or 100 Mhz required.
The 4X multiplier filter is already specified for 1960 to 2360 Mhz so shouldn't be a problem.
The required crystal would be about 4 Mhz lower ( 100 Mhz /4 / 6 ) = no issues there.
The only other bit might be a very slight tweaking of the Rx input track to the MGA86576.
My brief listening on the band from a suburban area ( 10 Kms east of the city, with a good outlook to the west) indicates all sorts of intermittent crud right across the spectrum from 2300 upwards. It seems to be a function of how many WIFI and other devices (legal and illegal) are located within close proximity.
Outside of Melbourne on Field days (even right next to a Telstra tower) all we hear on 2400 + is the required amateur signals.
Also, aren't we forgetting our New Zealand cousins whose band is 2396 - 2450 Mhz?
If we all drop down to 2300 then their case for a common segment either just below 2400 or even 2403Mhz would become more difficult to justify.
Cheers
Peter VK3QI
Whilst agreeing with Ross 3MY that the status quo should prevail for all the reasons mentioned, has anybody asked Mark 5EME whether the modifications required could be easily made to his transverter board?
The transverter 5 section hairpin filter is already specified for 2350 to 2450 Mhz, so I would have thought it a simple matter to add (snowflake) the requisite 1mm or so to each of the hairpins to bring the filter down the 50 or 100 Mhz required.
The 4X multiplier filter is already specified for 1960 to 2360 Mhz so shouldn't be a problem.
The required crystal would be about 4 Mhz lower ( 100 Mhz /4 / 6 ) = no issues there.
The only other bit might be a very slight tweaking of the Rx input track to the MGA86576.
My brief listening on the band from a suburban area ( 10 Kms east of the city, with a good outlook to the west) indicates all sorts of intermittent crud right across the spectrum from 2300 upwards. It seems to be a function of how many WIFI and other devices (legal and illegal) are located within close proximity.
Outside of Melbourne on Field days (even right next to a Telstra tower) all we hear on 2400 + is the required amateur signals.
Also, aren't we forgetting our New Zealand cousins whose band is 2396 - 2450 Mhz?
If we all drop down to 2300 then their case for a common segment either just below 2400 or even 2403Mhz would become more difficult to justify.
Cheers
Peter VK3QI
Re: That 13cm issue
Hi guys,
very interesting discussion. Let's have more stations on 2.4 - it would be good to hear you on field days in particular. Maybe next time Justin 2CU??
cheers,
Dan
very interesting discussion. Let's have more stations on 2.4 - it would be good to hear you on field days in particular. Maybe next time Justin 2CU??
cheers,
Dan
Re: That 13cm issue
The situation as I understand it...
The 13cm allocations really amount to two different but adjacent
bands, especially when it is difficult or at least inconvenient to
cater for both bands in one transverter.
None of the known transverters are capable of handling both "bands",
certainly not at the flick of a switch, some won't even go to the
other band at all. No-tune designs are a single band only AFAIK. For
most popular designs building a second transverter is more practical
than trying to modify an existing transverter to handle the two bands.
For 2300-2302 there are several transverter options available (DB6NT
and DEM) and for 2400 the options are different (DB6NT satellite band
transverter, Minikits).
The modular type transverter I have could be readily adapted to work
on either band. It would require only a different PLO and the
filters would need to be retuned.
But first what are the benefits of each band option?
Why use 2300?
1. to get away from QRM from wifi and cordless phone devices and
whatever else will be thrown into that band as time goes on.
2. to get more commercial equipment options
3. to be closer to the EME bands typically used elsewhere. However
EME users already cope with multiple allocations - in various ways,
including replicated equipment where necessary just to be able to
work JA VK and ZL as well as EU and the US.
4. using this band helps to avoid losing it (?) but only if there is
known, publicised activity
Why use 2400?
1. one transverter can provide local and satellite use
2. if you don't plan to use EME you don't need to listen or transmit
on 2300-02.
3. it's a bigger band but has qrm problems in the cities, the higher
you go in the band the worse it gets. The lowest "channel" of the
wifi channels is centred on 2425 and it is not a narrow band
modulation scheme! 20 khz spread is typical and there is stuff
hearable on 2403.
4. There is an option to use 2400 to avoid wifi QRM, if the LO and
hence IF chosen for the transverter design allows it. Unproven
whether this is effective.
5. Using this band helps to avoid losing it (?) but only if there is
known, publicised activity
The majority of potential contacts made on either of the 13cm bands
may well be contest contacts. A minority of users of this band use
EME and are keen enough to equip for whatever bands they need to hear
their EU, US and JA contacts.
One recent significant contact on this band was between vk9na and vk4ox.
Summary
1. Try 2400 to assess the qrm reduction.
2. Survey all users to see if a move to 2400 is easily done by a
critical mass, ie. at least the frequent contest users of this band.
3. Survey all users to see if a move to 2300 would be popular and achievable.
4. Do all this before any new transverters are built.
The 13cm allocations really amount to two different but adjacent
bands, especially when it is difficult or at least inconvenient to
cater for both bands in one transverter.
None of the known transverters are capable of handling both "bands",
certainly not at the flick of a switch, some won't even go to the
other band at all. No-tune designs are a single band only AFAIK. For
most popular designs building a second transverter is more practical
than trying to modify an existing transverter to handle the two bands.
For 2300-2302 there are several transverter options available (DB6NT
and DEM) and for 2400 the options are different (DB6NT satellite band
transverter, Minikits).
The modular type transverter I have could be readily adapted to work
on either band. It would require only a different PLO and the
filters would need to be retuned.
But first what are the benefits of each band option?
Why use 2300?
1. to get away from QRM from wifi and cordless phone devices and
whatever else will be thrown into that band as time goes on.
2. to get more commercial equipment options
3. to be closer to the EME bands typically used elsewhere. However
EME users already cope with multiple allocations - in various ways,
including replicated equipment where necessary just to be able to
work JA VK and ZL as well as EU and the US.
4. using this band helps to avoid losing it (?) but only if there is
known, publicised activity
Why use 2400?
1. one transverter can provide local and satellite use
2. if you don't plan to use EME you don't need to listen or transmit
on 2300-02.
3. it's a bigger band but has qrm problems in the cities, the higher
you go in the band the worse it gets. The lowest "channel" of the
wifi channels is centred on 2425 and it is not a narrow band
modulation scheme! 20 khz spread is typical and there is stuff
hearable on 2403.
4. There is an option to use 2400 to avoid wifi QRM, if the LO and
hence IF chosen for the transverter design allows it. Unproven
whether this is effective.
5. Using this band helps to avoid losing it (?) but only if there is
known, publicised activity
The majority of potential contacts made on either of the 13cm bands
may well be contest contacts. A minority of users of this band use
EME and are keen enough to equip for whatever bands they need to hear
their EU, US and JA contacts.
One recent significant contact on this band was between vk9na and vk4ox.
Summary
- If the vast majority of the contacts (likely to be) made are within
VK, the bands used elsewhere don't matter. [this was not intended to exclude or ignore ZL. I was just thinking of low power portable stations and where they were likely to make contacts. ] - If we have adequate suitable equipment options for 2400, the
unavailability of a DEM option does not matter. - Using the lowest end of 2400 has been suggested but the
outcome/verdict as to whether it really does reduce QRM problems is
not really known. Knowing it "should" is not as good as knowing "it
does". Also we don't know how convenient it may be for various
transverters to move down to 2400 (eg. if 2403 is at 144 or 145 on an
IF rig that can't tune below 144, then 2400 would require 142 or 143). - Using 2400-2402 may qrm satellite operations. What is known about
satellite usage of this band? Is there a segment that could be used
without causing problems to satellite users?
1. Try 2400 to assess the qrm reduction.
2. Survey all users to see if a move to 2400 is easily done by a
critical mass, ie. at least the frequent contest users of this band.
3. Survey all users to see if a move to 2300 would be popular and achievable.
4. Do all this before any new transverters are built.
Re: That 13cm issue
73
Iain Crawford - VK5ZD
Munno Para West, SA - PF95ih
Iain Crawford - VK5ZD
Munno Para West, SA - PF95ih
-
VK3XDK
Re: That 13cm issue
Gday all,
My flexiverter V1"L" and V2 boards can work on 2.3 and 2.4 (and 1296, 3.4) with suitable (switched?) filters.
I just got in some 3pole helical filters to suit 2.3Ghz (at great cost
) i am planning to build a filter "bank" with switchable filters to cover 1296,2.3 , 2.4 and possibly 3.4ghz all on one board for a true multiband transverter.
obviously may be a little while off.
Also though of experimenting with a YIG filter. May be able to track the filter with voltage control to suit each band.
LO generation to suit each band may be the next issue (my pll board will cover 1296, 2.3 and 2.4 LO's) There are other pll chips which will go from 400mhz (or so) to 4.4ghz, they are high in harmonics for an LO source but may be usable with some experimentation.
cheers, Graham VK3XDK
My flexiverter V1"L" and V2 boards can work on 2.3 and 2.4 (and 1296, 3.4) with suitable (switched?) filters.
I just got in some 3pole helical filters to suit 2.3Ghz (at great cost
) i am planning to build a filter "bank" with switchable filters to cover 1296,2.3 , 2.4 and possibly 3.4ghz all on one board for a true multiband transverter. obviously may be a little while off.
Also though of experimenting with a YIG filter. May be able to track the filter with voltage control to suit each band.
LO generation to suit each band may be the next issue (my pll board will cover 1296, 2.3 and 2.4 LO's) There are other pll chips which will go from 400mhz (or so) to 4.4ghz, they are high in harmonics for an LO source but may be usable with some experimentation.
cheers, Graham VK3XDK
Re: That 13cm issue
Graham,VK3XDK wrote:Gday all,
My flexiverter V1"L" and V2 boards can work on 2.3 and 2.4 (and 1296, 3.4) with suitable (switched?) filters.
I just got in some 3pole helical filters to suit 2.3Ghz (at great cost
obviously may be a little while off.
Also though of experimenting with a YIG filter. May be able to track the filter with voltage control to suit each band.
LO generation to suit each band may be the next issue (my pll board will cover 1296, 2.3 and 2.4 LO's) There are other pll chips which will go from 400mhz (or so) to 4.4ghz, they are high in harmonics for an LO source but may be usable with some experimentation.
Your flexiverter sounds like a perfect match for one of my PLL baords http://zl2bkc.com/2013/01/17/zlpll-announcement/. The harmonics will not impact the overall performance as long as you have some form of filtering before the mixer - this is a natural extension of the principal used to reject the image frequency. In the perfect world one would filter the RF side, filter the LO to be clean and use an non-reflective IF termination which is only a requirement for very high IP3 or broadband coverage (octage or better) using a single filter.
A concept worth experimenting with!
PS. You should also add 925MHz to that list for those fortunate to have access to that band (NZ and USA)
73,
Wayne ZL2BKC
Re: That 13cm issue
Wayne / Graham,
At the risk of dragging this thread a little further off topic....
I am also experimenting with a 2.4 / 3.4 GHz diplexer to route the signals to/from the appropriate BPF - instead of using a switch matrix.
As far as the future of 2300 - 2302 MHz is concerned I note that in Sweden they have recently seen a withdrawal of some 13cm spectrum.
A paper presented at last year's International EME conference entitled "Microwave Spectrum Issues" covers the topic very well, and highlights many of the issues being faced by the amateur microwave community.
http://www.uk.amsat.org/?p=10253
73
Rod Preston VK4KZR
At the risk of dragging this thread a little further off topic....
That's exactly what I'm trying to put together at the moment.Your flexiverter sounds like a perfect match for one of my PLL boards
I am also experimenting with a 2.4 / 3.4 GHz diplexer to route the signals to/from the appropriate BPF - instead of using a switch matrix.
As far as the future of 2300 - 2302 MHz is concerned I note that in Sweden they have recently seen a withdrawal of some 13cm spectrum.
A paper presented at last year's International EME conference entitled "Microwave Spectrum Issues" covers the topic very well, and highlights many of the issues being faced by the amateur microwave community.
http://www.uk.amsat.org/?p=10253
73
Rod Preston VK4KZR
Re: That 13cm issue
Well done to the ACMA who seem to be contacting anyone licensed to use this band.
Lou - VK3ALB
Being right doesn't excuse bad behaviour
Being right doesn't excuse bad behaviour
Re: That 13cm issue
They haven't contacted me . . . yet. 
73, Roger Harrison VK2ZRH
73, Roger Harrison VK2ZRH
Re: That 13cm issue
Struth Rog, you on the outer??VK2ZRH wrote:They haven't contacted me . . . yet.
73, Roger Harrison VK2ZRH
Rxd my (typically politically originated/formulated/flatulated)) letter in the mail today.
Cheers from a West of Everywhere Amateur
73
Andy VK6OX
If you can't explain it simply, you don't understand it well enough. Albert Einstein
Andy VK6OX
If you can't explain it simply, you don't understand it well enough. Albert Einstein
Re: That 13cm issue
Got my letter today. 
But I'm on wide band FM-TV spots, so it is of small consequence to my current operating situation.
Sorry to the ops who do use it.
But I'm on wide band FM-TV spots, so it is of small consequence to my current operating situation.
Sorry to the ops who do use it.
Mark, VK2GFR
Seven Hills
QF56LF
Seven Hills
QF56LF