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1
Morse Code / Re: XXX
« Last post by vwflyer on Today at 12:52:08 PM »
SOS recognition by skimmers would be very useful indeed. Itís a shame itís not implemented. With the miniaturization of HF rigs and subsiquent popularization of portable ops including popular activities like SOTA and POTA  more and more people are taking radios to isolated areas these days. This has also lead to a renewed interest in CW among hams. As good neighbors and safety conscious hams, we should see CW as a valuable and viable way for the growing number of portable operators to call for assistance. Skimmers should be made to recognize distress calls and perhaps some skilled and charismatic writer should campaign to revive the awareness of X X X. An article in QRZ magazine, on their webpage, on some popular CW, portable ops, and general ham radio podcasts. Spread the awareness and make X X X a useful tool in the portable operatorís toolbox.
2
Morse Code / Re: XXX
« Last post by gil on Today at 05:04:30 AM »
I don't think many people know about it.. I knew there was a "Pan Pan" in Morse but didn't remember what it was. Morse now being mostly a hobby, its value as a serious safety tool has been practically forgotten. I once asked the Reverse Beacon Network if they detected any possible SOS, the answer was no. It would be so easy to add a few lines of code to all those Morse skimmers to raise an alarm on detecting SOS or XXX.

I wouldn't count on it, but what else can you do? Sending an SOS would definitely draw LOTS of attention, but you might not need nor want that. I'd say use it and hope someone remembers... Otherwise, they might just answer your CQ to get a contact, no harm in that... Well, unless they give you a 599/73 and disappear!

Gil.
3
Morse Code / XXX
« Last post by vwflyer on May 20, 2018, 11:35:53 PM »
No, this post is not about Vin Diesel or adult movies. Rather, itís a question concerning the old practice of sending X X X in CW for Pan Pan, which is a call for assistance in non-life threatening situations. As a pilot Iím familiar with Pan Pan and I was curious if there was a way to call it in CW. So I googled it and discovered it was three xís sent as distinct letters. Iíve been messing around in CW for a few years now and never have come across this yet so it is not common knowledge like SOS is. I got to thinking about it as I was driving through a really isolated stretch of mountain roads last week, miles from cell service and thought that a way of getting the attention of a ham on the CW bands would be real handy if I had a breakdown and needed to have a ham relay a message for me to my wife to let her know about it and send some help if needed. I know SOS would bust a pileup and get a dozen of willing helpers in seconds. Do you think sending X X X would have any affect at all or am I better off just calling CQ HELP or something like that?
4
Antennas / Re: Mounting Antenna for NVIS vs DX operation ?
« Last post by gil on May 19, 2018, 04:13:22 AM »
That uBitx will serve you well. Keep us posted!

Gil

Sent from my SM-G928F using Tapatalk

5
Technical Corner / Re: Modding MTR4b for 13.8 volts..... possible ?
« Last post by gil on May 19, 2018, 04:11:26 AM »
The 7812 is not adjustable.. I did the diode thing once but the drop was more like 0.4V 1N4004..
Gil

Sent from my SM-G928F using Tapatalk

6
Antennas / Re: Random wire antennas and tuners
« Last post by CPR on May 19, 2018, 02:45:52 AM »
Thanks for the hints andy. Will do that.
Regarding the bad swr on the verical triband. It was caused from the radials not touching the ground. I staked them out so before, was a mistake.

Via TapaTalk

7
Technical Corner / Re: Modding MTR4b for 13.8 volts..... possible ?
« Last post by RadioRay on May 18, 2018, 09:56:16 PM »
If you simple need a voltage drop (not a current drop!) a couple of garden variety diodes usually give you a 0.9 volt drop per diode.  So, your 13.7ish can RUNNING can have diodes in the power line to drop it below 12 VDC , using your /cigar' lighter/power plug in the car.  I have a bunch of 1N400X series power supply diodes I've de-soldered from junk power supplies, which used for this at no cost.


>RadioRay  ..._  ._
8
Antennas / Re: Mounting Antenna for NVIS vs DX operation ?
« Last post by Andywragg on May 18, 2018, 05:24:06 PM »
Hi Gil,

The design I'm using is a Ham design, based on the military version. Its actually from DXEngineering (see my link earlier). To be fair I was only there, set up  for about an hour before it started to rain, so chances are with a bit more time on station I would have probably got a contact.

The FT-817 that I had on loan has now gone back to the owner and he's traded it for an FT-897 so my /P activities are somewhat curtailed until I can get my uBITX finished, and I'm still waiting for the case to arrive, or even be shipped. Alternatively I could go /P with the FT-450 and operate from the car but that would mean dismantling the shack.
9
Antennas / Re: Random wire antennas and tuners
« Last post by Andywragg on May 18, 2018, 05:12:37 PM »
I saw the other post earlier during my lunch break.

I'm assuming you haven't done this already...

The first thing I would do is take the wires off the "bobbin" PCB and using a multimeter  (set to check continuity) check the continuity between the BNC Outer and counterpoise bolt, and the BNC inner and the main radiator wire bolt. Also check for shorts across the BNC outer and inner. Do this in ALL switch positions, as you may have a faulty switch or you could have a dry joint on one of the toroids. I normally do these checks as part of the build.

Once you have verified the continuity of the PCB check the continuity of the wires, mainly the main radiator wire, but also the 4 counterpoise wires. Do the same check with your Coax feeder (Inner/outer/short test).

Lastly check your radio and tuner with a dummy load.

I scratch built mine and its pretty damned good for a homebrew antenna. No tuner required on any of the bands. And all I did was copy the QRP Guys schematic in the manual. But until I'd got the meter beeping on everything but the short tests I didn't hook it up to the radio.

Hope this helps

Andy

10
Technical Corner / Re: Modding MTR4b for 13.8 volts..... possible ?
« Last post by solaris0121 on May 18, 2018, 08:48:47 AM »
Thanks Gil,  id want something wired internally to run directly off car batteries/battery terminals  - im keen to have it all self contained if possible - I might even remove it all from the original box and re-box it with a ZM-2 (or similar)  in a single (more solid) case.... and a little active loudpspeaker and a switchable keyer.....along the lines of those project boxes youve been using lately.   Then I get options for resonant antennas, random wires and much more.

THe lithium Ion batteries - are they the 18650 you have been using.....   that was the plan for portable generally and the screw terminals for "emergency" power when required.

With an adjustable 7812 regulator I suppose I can adjust the transmit power as well.
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