Personally, extending any band well over its ITU allocated frequency assignment would be questionable for Amateur Radio use unless fully explained why it would need to be extended that far out. It would be in the best interest of Amateur Radio (in general) to canvass what the ITU has set forth for each band world wide and make the accommodations for all countries such that the LimeRFE functions in all areas of the world for the major operating bands (i.e. 160m, 80/75m, 60m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m, 2m, 70cm, 23cm, and so on) for the functional bandwidth of the LimeSDR. If youād like me to gather that data, please let me know and Iād be capable of doing that for you. Obviously, Hams also have side interests in other bands (aeronautical, etc) and those should be canvassed as well for major popular modes of listening - thatās more from a userās perspective than identified bands by the ITU.
Keep me advised if thereās anything else I can help with the development of this new board, Andrew -
I see no problem in having the LPFs & BPFs cover a wider spectrum. After all, this board is for experimentation. The people experimenting should know the applicable laws.
It is fact that I am HAM since 1974. but I am also professionally present
in aviation and avionics with main field of interest in safety and SAR
(homing in case of emergency)
Majority of now day HAM handhelds are able to RX on AM Air band and few are also
able to transmit on Marine FM.
Any way, in case you like to keep RFE strictly within HAM bands that is fine for me,
because we can always use wideband channel with custom filters.
For illustration, here one of my projects in GA, 2018. plane was 48 years old, vacum and majority of steam gauges out, glass cockpit in, full ADS B configuration nowā¦
Iāve been thinking about this quite a bit.
Would it be better to cover more ham/cell/wifi/experimental bands on TX & just cell/wifi/experimental on RX.
If you are going to have an HF section, look over the idea of a 50/70MHz upper limit, as many hf amplifiers cover this spectrum (I am an avid 6 Meters junkie).
Maybe a couple SMA jacks that can have a jumper removed on the pass thru RX/TX sections.
That way, people can switch in outboard BPFs for specific uses, as they see fit.
Getting or building bandpass filters for the enduserās needs could be their responsibility.
Letās face it, there are more folks using the Lime for RF research, than ham radio and there are many turnkey or hack options for hams (Prebuilt, kits, hacking a broken radio PCB).
So we are looking at the possibility of 6m and 4m support. For experimental use you have the wideband mode, where you are free to add external filters. The concern I have with moving too far in the general purpose/experimental direction is that it is a trade off and means compromising amateur radio band performance. That is, unless you grow the board further and then the cost goes upā¦
Iām inclined to suggest we keep this focused on amateur radio + cellular use cases, with a wideband mode as-is that supports experimentation with external components.
The LimeRFE incorporates a lot of feedback weāve gathered up until now and rest assured, we do listen. You can also be sure that, as with the LimeSDR family boards, if this proves popular and we receive a lot of great feedback and requests, it wonāt be the last RF front-end we produce.
Iām inclined to agree with all your comments - I do like the suggestion that Ed (AA7QQ) provided that there be at least one filter section that is allowed to be broken open to allow custom filtering - even if it was a completely separate path for custom use for anyone. It might be great to have a wideband preamp in that path, too, thatās jumperable (in/out), too. Otherwise Iām jazzed about the prospects of this new board - keep us all advised.
$599 ?!
(only 10 early birds at $499 gone already)
Personally I was expecting $300-400 price levelā¦
May be Lime expects funding of 30-40 units, only?
The board has quite a bill of materials and I think if you compared the cost with the alternative of putting something similar together with off-the-shelf modules for the bands covered, it will come out quite favourably. Add in a LimeNET Micro and you have a sub-$1,000 solution that covers a lot of bands, with decent power output and of course support for more interesting modes.
Can you show me another solution, off the shelf or even DIY, that provides the same sort of coverage for a similar price? Genuinely interested and if there are Iād love to find out more!
HF filter boards are very simple in design and can easily be bought. Add them to the RFE and it would have become much bigger and theyād be affixed to Rogers PCB substrate, which would be over the top and have pushed the cost up quite a bit.
If youāre mainly interested in HF it may seem overpriced, but as a single integrated solution covering many bands, it replaces a lot of boards and modules which bought individually would cost far more.
I could buy a replacement filter board for almost any Radio for less. (They are only like $100-200) even for 2m and 70cm.
Also I would have hoped myriadrf (Or Lime or who ever they call themselves now) would have finished making products work before adding more seeing the high amount of defective limeSDRs really makes you wonder how go this board might even be.
A filter board. Which presumably does not include any PAs or LNAs.
Also 2m and 70cm are still pretty pedestrian RF technology wise. Whereas when you get up to 23cm, 13cm and 3.5GHz it becomes a bit more exotic. I know of COTS amateur radio transceivers that go up to 23cm, but none that go beyond this.
MyriadRF is an open source initiative. Lime Microsystems are a vendor. Think like Ubuntu and Canonical. If you have faulty hardware thatās in warranty feel free to DM with details.
So this board has some form of PA? (As meantioned in above posts.) is there a way to get the signal thatās used for the Tx Rx switch for use with out this board for external PAs for people not willing to risk $500+ on a board that will have I suspect just as many problems as the LimeSDR itself.
It has more than a single PA ā it has many, plus multiple LNAs also, and band and notch filtering, plus protected GPIO for e.g. coaxial relays. Itās all on the Crowd Supply page, but hereās the block diagram.
