Radio Preppers

General Category => General Discussion => Topic started by: gil on August 22, 2017, 01:51:20 PM

Title: Crowd Funding The Perfect Survival Radio?
Post by: gil on August 22, 2017, 01:51:20 PM
Hello,

You know I've been thinking about the perfect survival radio for a while, first proposing a CW-only transceiver. Only fools never change their mind, so here is what I have come up with now:

The choice of DSB is dictated by the need to interoperate with military radios which use USB only. I am thinking of a minimalist concept, less is better.

I wonder if a radio designer could be hired after a crowd funding campaign... What are your thoughts on this?

Gil.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: paul5.wolf on August 22, 2017, 03:26:57 PM
Hello,

You know I've been thinking about the perfect survival radio for a while, first proposing a CW-only transceiver. Only fools never change their mind, so here is what I have come up with now:
  • Quad band, 20, 30, 40, 80m transceiver.
  • CW and DSB modes.
  • Keyer optional but real CW with full QSK.
  • 3kHz and 400Hz filters.
  • General coverage receiver.
  • 10W output.
  • Low current draw on receive.
  • Watertight case and connectors.
  • Battery in the case.
  • Built-in battery charger (3x 18650?).
  • Military handset or speaker-mic.
  • SWR indicator.
  • High SWR protection.

The choice of DSB is dictated by the need to interoperate with military radios which use USB only. I am thinking of a minimalist concept, less is better.

I wonder if a radio designer could be hired after a crowd funding campaign... What are your thoughts on this?

Gil.
The perfect survival radio would work for anyone.  He may not know code.  If it's survival, it's protection of life or property hence emergency-- legal regardless.  I like your idea to take a punch at a perfect survival radio.  Those who don't know code may know "SOS.". ANOTHER idea might be a few perfect survival radios each mimimal for their purpose.  Before I knew much about JT65, my thoughts ran to whether radios all set to a few  channels that were capable to transmit/receive as self contained units could do about anything in anyone's hands.  But, then behold those tiny messages and all the technicalities.  You are on to something good.

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Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: swxx on August 22, 2017, 08:50:58 PM
Hello,

You know I've been thinking about the perfect survival radio for a while, first proposing a CW-only transceiver. Only fools never change their mind, so here is what I have come up with now:
  • Quad band, 20, 30, 40, 80m transceiver.
  • CW and DSB modes.
  • Keyer optional but real CW with full QSK.
  • 3kHz and 400Hz filters.
  • General coverage receiver.
  • 10W output.
  • Low current draw on receive.
  • Watertight case and connectors.
  • Battery in the case.
  • Built-in battery charger (3x 18650?).
  • Military handset or speaker-mic.
  • SWR indicator.
  • High SWR protection.

The choice of DSB is dictated by the need to interoperate with military radios which use USB only. I am thinking of a minimalist concept, less is better.

I wonder if a radio designer could be hired after a crowd funding campaign... What are your thoughts on this?

Gil.
I think it is a great idea. Perhaps even made in China provided proper QC is done and it keeps costs down. But QUALITY is KEY as it has to be reliable. I'd add to the above:

* Balanced output and built in tuner -- PFR3 does this and I think that's great as doublets (double zepps) work well, even vertically
* In the tropics, I think 40m acts like 80m does in Europe. So having 15/20/30/40 would be good for such locations.

I'd also like to see an Auto Alarm built. I may make a separate thread on that in the forums. If that can be incorporated in a CW Surival Rig I think that would be very cool, but even if it is a plug in addition or option.

The lack of being able to find any one rig that meets the above specifications on your list is what has prevented me, along with impecuniousness have prevented me, to date, from doing what I consider a priority. I have pretty much everything else communication wise: well versed in Morse, able to copy signals -13dB SNR by ear, home brew antenna experience, keys, but what is lacking is the RIG.

All I have at present is one of those current-guzzling ones that needs a car battery, and that battery won't last for long.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: km4mcm on October 31, 2017, 03:24:59 AM


i think its a great idea. but would the ability to atleast monitor the air bands or marine bands be important? offering an ability to know if someone who may not be on hf could be close enough to see a visual signal or close enough to keep your eyes open to avoid being found if thats is needed.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: gil on October 31, 2017, 03:44:18 AM

i think its a great idea. but would the ability to atleast monitor the air bands or marine bands be important? offering an ability to know if someone who may not be on hf could be close enough to see a visual signal or close enough to keep your eyes open to avoid being found if thats is needed.
Yes, that's what a "General coverage receiver" does. Air band would be difficult to do but no problem for marine HF.

Gil

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Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: Andywragg on December 11, 2017, 11:53:24 AM
Have you seen the UBITX? Just released for sale, and would appear to hit a lot of the features you are looking for. I look like having to sell another kidney......
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: caulktel on December 11, 2017, 01:24:45 PM
Hi Andy,

I was just going to suggest the same thing. I ordered one and will report on how well it works.

Joel
N6ALT
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: Andywragg on December 11, 2017, 04:39:06 PM
I was just reading the BITX40 group pages and they've already sold out the first batch of UBITX kits. It's going to be a minimum of 3 weeks before any more are available.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: cockpitbob on December 11, 2017, 05:10:26 PM
Does anyone know how much power the uBITX draws during receive?  Battery life is important and nearly an obsession in this forum 8).
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: gagcon on December 11, 2017, 07:48:31 PM
Sounds like the KX3 in a waterproof box.


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Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: caulktel on December 12, 2017, 10:53:56 AM
Does anyone know how much power the uBITX draws during receive?  Battery life is important and nearly an obsession in this forum 8).
+

I'm not sure anybody knows yet Bob, but I'll bet it's not that good with a Arduino and a 16X2 display on top of what the radio itself draws. I will ask on the Bitx Group and see if I can get a answer.

Joel
N6ALT
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: Andywragg on December 13, 2017, 03:49:20 AM
I did some digging on the group, it's already been posted.

From Farhan himself....

"Rx draws 150 ma on zero volume. It can go up to 200 ma on peaks.the tx draws south of 700ma without modulation, peaks to 2.5A on modulation."


Hope this helps
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: NWARadio on December 30, 2017, 10:38:54 PM
Does the Yaesu 817 not meet all these needs?
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: gil on December 31, 2017, 07:42:53 AM
The 817 does not qualify in the most important aspect of any survival radio, current draw on receive, which is the only reason I haven't bought one yet. Now, with the advances in battery technology and solar cells, the problem isn't as acute as before, but today it is possible to do much better, like the KX2, which unfortunately fails in the ruggedness department, especially regarding water ingress.

Gil.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: scarr on January 01, 2018, 04:10:20 PM
For me (ymmv) the 817 is a great compromise due to its low cost, small size, available bands and modes.

Yes current draw is an issue if it's your sole radio - but, I think the issue is somewhat overstated: current draw in my experience is around 350mAh. Compared to a MTR trx, this is absolutely huge, but, the FT817 is not an MTR. How about comparing it to the Clansman RT320?

RT320 = 24 volts * 175mAh = 4.2 Watts for RX. Pro: 30 Watts out. Extremely rugged. Con: Big and weighs 5kg without battery or other options. 
FT817 = 12 volts * 350mAh = 4.2 Watts for RX. Pro: Small and weighs 1kg. Con: Max 5 Watts out. Not nearly as rugged.

In short, the 817 is a lot easier to carry around on your back - it's far from perfect, but given the choice it's what I have picked.

If I really was concerned about having a long term, portable, backup HF SSB rx capability, I'd have a relatively inexpensive radio like the Tecsun PL660, which will run off AA's for an eternity.

Elecraft radios are lovely but they cost a fortune in the EU. If I was taking part in SOTA, I'd grab an MTR.

I will be picking up a ubitx shortly, the plan being to put it in a rugged case and make a poor mans PRC320 :)

(A more detailed description of the 817's RX power consumption is available here: http://www.ka7oei.com/ft817_pwr.html - which demonstrates that it's possible to power the 817 on RX at 7.5V, with 290mAh drain, for an effective power consumption of just 2.18W.)

Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: gil on January 02, 2018, 06:36:42 AM
I don't dislike the 817 mind you... I might yet buy one, if only for the 2m and 70cm bands in SSB.

Gil.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: Andywragg on January 02, 2018, 07:01:53 AM
How about approaching Farhan (of BITX40 and UBITX fame) with regard to 'hardening' the UBITX for the/our intended use? As far as I can tell, the UBITX fulfils most of the radio specific goals, with the exceptions being the enclosure and battery.

For me having an internal battery is a negative attribute, as typically I'd want a number of battery packs that are easily swappable. No point having a radio you can't use cos the battery is flat (in the field away from charge facility or in the middle of the night when there's no sun to solar charge).
I speak from experience here as a former military signaller, experienced in pretty much all the PRC 3** Clansman range. Whilst these are bombproof radio's I wouldn't want to lug one (HF Variety) around as a civvy due to the weight of the pack and the cells.

When funds allow I shall be getting hold of a UBITX and looking to source a suitable field style case in which to install the guts of the radio.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: scarr on January 02, 2018, 05:15:48 PM
Farhan is an RF wizard - he'll design and build the magic circuitry, but it's probably for another enterprising soul to make rugged aftermarket cases - there are nice desktop cases made for other members of the BitX range: https://amateurradiokits.in/store/metal-enclosures/

Ideally I'd love stackable components what would click on to the case e.g. ATU/Battery/amp/empty cases to roll your own add ons.

As others here have found out - loose wires are a pain in the butt and prone to failure in the field/backyard.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: gil on January 03, 2018, 06:28:09 AM
The uBitx would indeed be a good candidate for boxing up in a military grade case.

Quote
Ideally I'd love stackable components what would click on to the case e.g. ATU/Battery/amp/empty cases to roll your own add ons.

Definitely. My PRC-320 works that way. You clip the battery on. Also the PRC-351, with a bolt-on tuner and the same battery.

Writing Farhan is a good idea, I will do that.

Gil.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: Andywragg on January 06, 2018, 05:21:28 PM
I just ordered the uBITX. It's on backorder so it will be a while before it arrives.

As for a case/enclosure.........

So of the builders  are using a cheap plastic case off Banggood for less than 10. I might get one of these and wrap it in Gorilla tape, after running silicon sealant over all the long joints.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: scarr on January 06, 2018, 07:36:06 PM
That's great Andy! I have ordered one too. Over time I'm hoping to be able to put a tuner, NESCAF filter and battery in the case, so the only wires outside will be for the key, headphones and antenna

I've got an aluminium tin that came with a present, which I'm going to use as the test enclosure. If everything works and goes well with that, I'll look at getting something a bit more solid afterwards.

The tin is gold coloured, so it's going to look eh.... interesting...  even without my dodgy slicing and dicing for the display etc  ;D


Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: cockpitbob on January 07, 2018, 03:15:30 PM
For what it's worth, there are two 3D printable cases for the uBITX on thingiverse
https://www.thingiverse.com/thing:2745287 (https://www.thingiverse.com/thing:2745287)
https://www.thingiverse.com/thing:2732866 (https://www.thingiverse.com/thing:2732866)

I've made a couple cases for RF stuff on my 3D printer.  For shielding I line it with copper tape.  This makes for a very light enclosure.  12feet of 1" copper tape is only $3 on banggood.com.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: Andywragg on January 08, 2018, 03:32:00 AM
Thanks Bob.
Just out of interest, how much does it cost to print a box?
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: cockpitbob on January 08, 2018, 10:30:55 AM
Thanks Bob.
Just out of interest, how much does it cost to print a box?
I have a 3D printer and for the common materials (PLA or ABS) it's about $0.75/oz.  It's even cheaper than you might think because for areas of an item that have a lot of volume you tell the printer software to fill the areas with honeycomb of whatever density you want.  I use anything from 20% "infill" to 100% infill.  It saves weight, materials, print time and you lose very little strength.

Printing is a slow process.  I think printing all the parts for a uBITX box would be about 15hrs of printer time.  That's OK since it takes 5 minutes to set up a print, then I just let it run over night.
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: Andywragg on January 08, 2018, 10:47:55 AM
How big is your printer?
Title: Re: Crowd Funding The Perfect Survival Radio?
Post by: cockpitbob on January 08, 2018, 10:59:20 AM
This is the one I have.
https://robo3d.com/products/r1-plus-3d-printer (https://robo3d.com/products/r1-plus-3d-printer)
I got it 2.5 years ago mostly for my "engineer from birth" son.  I paid $850 for it.  It's print volume is 10" x 9" x 8".  Of course you can make bigger things in multiple pieces and glue them together.  Printers keep getting cheaper.  There's $250 kits that take about 6 hours to screw together that work very well(sorry I can't remember the names).

Bare in mind that there's no magic in these printers and often not a lot of difference between the $300 and $1,000 ones other than a pretty enclosure, display and no need to be connected to a computer.  They all have a heated print bed, 3 axes of stepper motors, an extruder and a controllable print cooling fan.  Most use the exact same set of Arduino boards and software to run them.  The good ones are a bit more accurate because they are stiffer.  The expensive ones use guide rods bigger than 6mm, but my printer with its 6mm guide rods does great work.