Bitcoin donations to: 1CE9UfWJcHBYkWPns7iqBqZgKhd5xfqEaM thanks!
Buy Bitcoins easily by clicking HERE!

Recent Posts

Pages: 1 2 [3] 4 5 ... 10
21
Morse Code / The One-Watt Magic Number.
« Last post by gil on June 15, 2018, 08:38:19 AM »
Hello,

Trying to make a contact again with my Pixie and maybe 300mW, I recalled most of my past QRP and QRPp attempts using CW. Usually, anything a Watt and above is no trouble at all with a full-size antenna. I even made a contact once from Florida to Estonia (5K miles) using 1.3W! Even my Rock-Mite on 40m seemed to work fine, though the issue was more of a receiving one, because of the lack of selectivity. Then we get down to 500mW, where contacts are still possible, just a bit harder. Below half a Watt things become very dicey, though I have tested 100mW successfully on more than one occasion with Ray 820 miles away. For calling CQ however, one Watt seems to be the practical limit. It gets better from there on up, of course, up to five Watts or so, after which adding power doesn't seem to do much more, at least when conditions are somewhat favorable.

This brings me again to the conclusion that QRP radio designers know their business. Aside from Pixies, Rock-Mites and such, which are fun novelties, great practical radios start at around two Watts. I especially like the SW+ series (ME+ now), and of course, the Weber MTR rigs for QRO operations  ;) I would love to see a surface-mount SW+! Instead of adding current-hungry features, what don't we make radios smaller? We have the technology with SMT components. There should be rigs out there the size of a small box of matches. The limiting factor should be the connectors and controls.

Anyway, just rambling... I think a practical radio should have a minimum of around 2-3W to be safe, with 5W being great. One Watt could get the job done but I would not count on it. Below one Watt you're just having fun, and that's great. BTW the 817 with a less than a full battery outputs 2.5W and people make plenty of contacts with those, even using SSB.

What do you think is the practical power threshold for a CW-mode survival radio?

Gil.
22
General Discussion / Re: Looking for Survival Camp Ideas
« Last post by vwflyer on June 15, 2018, 02:46:01 AM »
Agreed! Avoid real distress calls!
A simulated emergency call should have some goals to be met to prove that the exercise  was successful though. When organizations like ARES demonstrate their abilities to public service agencies, they have to show the value of the radio by proving that important/life saving communications can reliably be handled by their radios. They do this by transmitting non-important but equally challenging messages. Things like your coordinates are a good test of successful communication since it's something that can easily get messed up in the transmission with all those numbers (number don't have context to help fill in the blanks), and it's something that would likely have to be transmitted in a real crisis. It also involves other survival skills like being able to read a map or use a GPS, so it ties the radio in with the rest of the outing.
23
General Discussion / Re: Looking for Survival Camp Ideas
« Last post by gil on June 14, 2018, 02:00:20 PM »
I suggest not using words like "Mayday" or SOS in Morse... Even for a simulation, and even with a warning.

Gil.
24
General Discussion / Re: Looking for Survival Camp Ideas
« Last post by vwflyer on June 14, 2018, 01:43:07 PM »
And as for simulating a distress call, perhaps you can prearrange a call with a ham you know. Have the scouts provide you with coordinates from a map or gps. Make it vary clear on the air that itís an exercise or simulation and make the information passed benign so that other hams donít get excited by tuning into the middle of the QSO.
If you can set up a 60 or 80 meter wire you can be pretty sure of solid local QRP contacts using NVIS.
25
General Discussion / Re: Looking for Survival Camp Ideas
« Last post by gil on June 14, 2018, 01:23:53 PM »
Morse code with flashlights! Then have them try to decode slow code on the radio...

Gil.
26
General Discussion / Looking for Survival Camp Ideas
« Last post by N4AE on June 14, 2018, 11:40:06 AM »
Hello from Chicago.  Hope everyone is enjoying time outside, especially with Field Day upon us.

I'm looking for some ideas to incorporate radio into a survival exercise with my Boy Scout Troop.

Each December, we take to the back woods of Michigan for a weekend survival camp.  The boys dig trenches, build shelters, and sleep in the snow.  They make their own meals with limited provisions.  It's an individual effort and the boys learn that they can make it using the Scoutcraft they know.

This year, I plan to bring along my Field Expedient Station (FT-817ND, Chameleon Emcom III Portable) without digital.  Just phone for simplicity.

My first thought is to demonstrate how to build a hasty antenna deployment.  Maybe an end-fed inverted Vee.  Simulate a distress call (not sure how I will do that).  Try to make contact in the daytime (groundwave) and night (skywave).

I would appreciate any input you have.

73,

Brian
27
Digital Modes / Re: I tried FT8 last night!
« Last post by gil on June 14, 2018, 07:54:15 AM »
I have had some luck on 80m and 2m USB... Otherwise it's 599-73, sad indeed.
Gil

Sent from my SM-G928F using Tapatalk

28
Antennas / Re: Random wire antennas and tuners
« Last post by CPR on June 14, 2018, 07:32:00 AM »
Will try that. Thank you!

Via TapaTalk

29
Digital Modes / Re: I tried FT8 last night!
« Last post by CPR on June 14, 2018, 07:28:27 AM »
Sure won't do that again! :o

I knew it probably wasn't for me, but with all the hooplah, I had to give it a try, at least to know what I'm talking about if ever that conversation pops up in good company... I even made one contact. For me, it's like watching paint dry, utterly useless and uninteresting. I'm not bashing FT8 users or even FT8 here, but it just isn't for me, by a very long shot.

I used the same software however for WSPR, to see my antenna radiation pattern, very useful, got Venezuela on 40m 2W. Of course with WSPR you don't put anything in your log, but I couldn't care less about my log. I actually only input contacts maybe half the time, when I don't lose my notes, forget to write the date or call signs...

Radio for me is about human interaction if only to ask what antenna someone is using... A few words about the weather, even a simple FB, exchanged between two people, make my day.

Gil.
I am new to ham but my few contacts were just signal reports for the log :( as soon I try to start a conversation, the other hams block with 73. It's quite sad.

Via TapaTalk

30
Antennas / Re: Random wire antennas and tuners
« Last post by gil on June 14, 2018, 06:56:12 AM »
Try a clamp-on toroid choke and slide it on the coax for best SWR...

Gil.
Pages: 1 2 [3] 4 5 ... 10