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Topics - daedalus

1
A while back I was trying to imagine what I would do in the aftermath of a SHTF once I had established a degree of security.

Knowing what is going on and who else is out there would (for me ) be of high importance.

I realised that being able to scan big chunks of frequency across all bands would be desirable, also to be able to do this quietly. This led me to think a panadaptor waterfall would fit nicely (if the power consumption can be managed) and to be able to scan from ELF all the way up to the satellite GHz.

The only solution I found for this was SDR (Software Defined Radio) , the traditional "super heterodyne" receivers would only do sections of the spectrum and the waterfall bandwidth was not great (for this purpose)

What amazed me further was that the radio hardware was only $30 ! I have only just started exploring the area of SDR for disaster prepping but I see a lot of potential , I'm possibly late to the game but hopefully there is enough time left for me to get a working SDR setup.

Would be very interested to hear what Radio Preppers think about SDR, we have a dedicated section now
2
General Discussion / Suggestion for new Forum topic - SDR
November 10, 2019, 10:55:14 am
Has a dedicated forum topic of SDR been discussed ? From a prepping perspective its got many aspects and seeing as it is most likely the future of transceivers it could be interesting to look at it separately.
3
General Discussion / SDR vs superhet : after disaster
November 10, 2019, 12:41:48 am
It definitely looks like the future of transceivers is SDR, this got me thinking: if there is a disaster with long term effects then the key aspects of transmission equipment will likely be :

1) reliability
2) repairability
3) durability
4) replacement parts
5) low power consumption
6) adaptability
7) portability

I would say 1-4 favours the superhet and 5-7 favours the SDR, although with 5) power consumption the laptop/tablet power consumption may need to be taken into account

So this probably means one of each , say an FT-817ND and one of the new SDR that is self contained (QSX, IC-705 TX-500)

That got me thinking, how best to use two transceivers (i.e. a superhet and an SDR) and I began to wonder, would it be possible to reconfigure the SDR to act as a power amplifier for the FT-817 ? or even to act as a digital modes device for the FT-817

4
Antennas / Magnetic antenna query
November 06, 2019, 11:38:52 pm
How does a magnetic loop "know" it is to pick up magnetic waves and not electric , probably something very simple and if so apologise for asking !
5
Antennas / antenna theory - fundamentals
November 06, 2019, 11:37:18 pm
After watching the excellent videos on end fed half way antennas on the RadioPreppers youtube channel, I realised I did not have an instinctive i.e. fundamental understanding of how an antenna radiates. After much research, especially in the physics forums, I started to build up a new analogy that I haven't explicitly seen before, its sort of drawn from lots of sources of information.

It is very rudimentary at the moment , I'm starting with visualising a DC pulse along on open wire (the most basic of basics) and aim to build up from there.

The questions I have are :

1) Is this something that might be of interest on this forum
2) Are there any other people who might be interested in collaborating, I really could do with someone to bounce my thoughts off, either on the forum or offline
6
Classifieds / swap : Ft-857 & E92D for SDR
November 06, 2019, 12:02:33 am
I am looking to move to an SDR transceiver and would like to offer my Yaesu Ft-857D (BNIB) and also Icom E92D as possible swap equipment, any country considered because I travel a lot , can use cash to balance !
7
I am looking at SDR transceivers but can see power and reliability problems with running a laptop. I considered a tablet but assuming no internet after a disaster I don't think this will be very reliable (any updates typically need to be verified which means internet !) . So have several questions :

1) Is there an SDR transceiver that is self contained and can do all the digital modes plus auto CW and can be reflashed without internet

2) Is the raspberry Pi a realistic alternative to a laptop for driving an SDR transceiver

3) Is there a way to open up an SDR transceiver to TRANSMIT on ANY frequency within its upper and lower frequency , I can see its easy to listen on any freq
8
I have massive problems with the letter captcha currently being used due to vision impairment

It is probably the worst one I've encountered in many years.

Would it be possible to get an audio or a more visually impaired friendly captcha (google or wikipedia works well)
9
General Discussion / Encryption
November 05, 2019, 06:08:31 am
I have several queries related to encryption :

1) It is my understanding that encryption is only banned for Ham transmissions, there doesn't seem to be any such restriction for the non ham, this opens the door to experiment with encryption methods that could be used after a disaster

2) What encryption method would likely emerge as the dominant standard assuming no internet and therefore no side channel or central repository to pass keys etc

3) How easy would it be to encrypt voice using ham SDR transceiver
10
General Discussion / https for the login ?
November 05, 2019, 04:31:22 am
Would it be possible for the site to get a certificate (they are free from lets encrypt) so that the password doesn't transit in the clear.

my password manager screams at me in a bog red banner every time I login !!