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Topics - CPR

Pages: [1]
1
General Discussion / 73s from Croatian Adria
« on: August 08, 2018, 05:28:08 AM »
I am on vacation atm and tried out some setups with sea as a reflector. Quite surprising results...

https://youtu.be/IKrAj1hCdh4

https://youtu.be/Cbc9gpA9hak

Via TapaTalk


2
Technical Corner / Digital modes for preparedness
« on: July 10, 2018, 10:51:47 AM »
Howdy,

with getting the Wolphilink for my 817nd a whole new world opened. Initially, I wanted to get that thing for comparing my homebrew antennas and see how they perform in different environment. But now it came to my mind, I can use it for much more! (not for chatting or making qso via android phones  ::) )

Weather faximile
I am living in southern Europe, I found an old website from 2008 and I don't know what frequencies are in use for weather faxes. I think it is a great thing when bugging out. I can power all my gear via USB solar charger, therefore I can be quite independent with my QRP setup. I think a weather forecast is a very valid information to have access to. So, my questions to you guys is, where can I get actual frequencies for them?

Time and date
Are there beacons out there telling the current time and date? (except the ones for radio controlled clocks?)

Access to emails
Sending emails is also a nice addition. As I am new into that I am not quite sure if it's possible via Android too but I assume it is.

As I am not quite into that network things I can't tell anything about it. But I am like a sponge for new information, so if anyone has knowledge to share, I am eager to hear it :)

73

3
Antennas / Linked Dipole
« on: June 20, 2018, 08:29:30 AM »
For quite a time I was interested in building a resonant multiband dipole or linked dipole.
I see a lot of benefits in it, especially no tuner is needed therefore no loss for qrp. Although you have to carry a bit more of equipment, the linked dipole should perform the best regarding noise and stuff - so they say.

Anyway, I got myself the dipole center with a 1:1 balun kit from sota beams.
I found a great tutorial on how to trim the wire :

http://amateurham.co/4-band-linked-dipole-how-to/

So in the following days I intend to build the linked dipole and will keep you updated.
I'm quite curious about the performance compared to the random wire end fed antenna. I intend to use this linked dipole with my 6 meter telescope pole.



Via TapaTalk


4
Antennas / MFJ 971 vs LDG Z-817
« on: June 08, 2018, 04:51:04 AM »
Hello guys,

I am about to buy my first real antenna tuner. Although I got the QRP Guys Z Match tuner, I wanna have something more powerful for scalability.
I am currently really struggling on what to choose. My favorite is the MFJ 971 tuner. It's small and can be set to QRP use (max 6W) with integrated SWR and power meter. Also it can be used with higher power (for the time after I get an MX P50m amp).
But somehow the autotuner from LDG got into my head, it's smaller and more portable. But it can only do 20W max...
Can someone show me the pro's and con's to each tuner?
I don't wanna waste my money...
I really appreciate any information!

ATB
CPR

5
I don't know if it's legit to talk about this here. I am just pissed at the moment!
I read about an Iraq and Turkish guy in Germany who raped and tortured a 14 yrs old girl and then killed her. The Iraqi has a rejected Asylrequest but was still in Germany - legally - although having a pretty extensive file at the police. I don't want to be racist here and this post is not intended to be racist, it's just about the current situation.
We are not seeing any of this in the mainstream news. Hell, in Croatia nothing is reported about immigration anymore - it's ignored - if it's not in the news it is not happening, right?
Our government was not able to protect our borders when the big immigration wave came. I envy Hungary, they have done it right. Croatia can't secure it's border because its just way to long, the borderline outlines whole Bosnia and Hercegovina. So, I assume that is also the reason why we are struggling to get into the Schengen agreement.
I live at the transit zone in North Croatia, all the traffic going to Europe goes through my town (heading Maribor - Graz - Salzburg - Munich). Thank god the migrants went over Ljubljana so we were spared of looting and civil unrest - although we prepared for it.
Some folks here prepared food and stuff. Very kind - but dont be stupid. Most of those are young aggressive men.
Slovenians closed the borders, very clever. So the immigrants had to stay in Croatia - again, the government was not ready (they are never ready for anything, they are incompetent here)...
Anyway, I often see civil unrest videos in France, as there is a big percentage of muslims so there are more cultural friction points. I am curious what's going on there?


6
New To Radio / QRP from a beginners view
« on: June 01, 2018, 03:53:37 AM »
Hi,

I want to share with you guys my adventure of becoming a ham operator. I got my license and myself a 817nd. The reasons for the 817 were primarily the low power consumption and easy powering in the field without carrying heavy loads and expensive equipment. That was crucial for me as I am on a tight budget for that kind of things. Most of my budget goes into my homestead so I had to really struggle with what to buy. I wanted a rig that was scalable if necessary but stripped off if I need a light and portable rig. You know, that kind of a rig that fits in a sidepocket of your bug-out bag. Or if you want to make a contact, so you don't haul 10kg of gear up a hill. Buying a tuner+50Wamp brings me to the same price as the 100W rigs. So I don't see a mistake in buying the 817nd.
When I first got the 817 I thought: holy shit that thing is small! I have big fingers and takes some efforts to reach the buttons at first. BUT, it can do everything. HF, VHF, UHF and thats the thing that got me, plus it can run on batteries for hours. I even listened to airband some day and tracked the planes on an Android app. You can do everything with this thing, I didnt even dig into digi modes yet. I think this is the best radio for emergency preparedness. It's small, lightweight, low power, multi-talent, solid built.



The next thing was to get my first antenna. Although I prefer to build my own stuff, I ordered the QRP Guys Triband and the Z Match Tuner. I had real issues on tuning the 40m band, I removed 4 windings on the toroid which is loading the antenna to get it somewhat below 2.5 and then with the tuner I can get it below 1.8.  Antenna + Tuner = 50$. Nice budget friendly price.
My next project is a linked dipole and an EFHW antenna. I got the wires and everything already done, I am waiting for the toroids to make a 1:1 balun for the dipile and a 9:1 unun for the 9:1 endfed.

My first time going on air was just recently. And I can say, with QRP it is soooo difficult to get a contact. No one hears you. Maybe it's also the antenna (can't wait to finalize the dipole and the efhw). The funny thing, all my contacts until now where from Belgium and those station where some club/special event/anniversary stations...  So I assume they had very powerful antennas high up in the air so they could hear me.



Yesterday I spent the whole day on my homestead, slowly grilling a chicken and doing some QRP. All day = 3 contacts.

Another almost succesful contact was a German somewhere around Hamburg. The sad thing is, he didn't even try to copy my signal twice. After the first time he repeated half of my callsign and the second time he said "negative copy", and took the other station. Pretty rude  >:(
Anyway, I had succesful QSOs over 1000km away. What a thrilling experience  ;D

7
Antennas / Random wire antennas and tuners
« on: May 17, 2018, 09:22:06 AM »
I got myself a Z Match Multi Tuner from QRP Guys. With 35$ its quite cheap, but winding the toroids is a pain in the butt.
First, a question about the functionality before I head over to the random wire antennas. I hope that's okay and won't be classified as offtopic.

Yesterday I tuned my triband vertical and decided to try out the tuner with the vertical to see if it does something.
When I switch to "TUNE" I can get the SWR down to 1.1. As soon I switch over to the "OPERATE" position the SWR jumps over 10.. I was using my Mini60s attached to the tuner going then to the antenna. I thought maybe the power of the mini60s is to weak to get a reading on operate, but I am not sure and pretty clueless if the tuner is maybe malfunctioning.

Another question is the random wire, assuming the tuner works, I thought about attaching the random wire and use it as an endfed antenna! Would be the cheap option for now, as my favourite endfed multiband is the mini from HyEndfed and with over 100 it's clearly over my budget at the moment.
Anyway, I found a good website about random wires: http://udel.edu/~mm/ham/randomWire/

Does anyone have any experience on the "best" length given: 
Quote
A standard recommendation (see QST, March 1936, p. 32, "An Unorthodox Antenna") is an 84' long end fed and a 17' long counterpoise (6.5' for 20m)

How do you layout the counterpoise at a random wire? Do you have to adjust the length of the counterpoise depending on the band tuned or does the tuner take over that part too? I don't understand what they mean with this 6.5' for 20m in the bracket.

Best,
CPR


8
Batteries & Solar / Salvaging old Notebook battery
« on: April 09, 2018, 08:21:43 AM »
Hi,

I just found an old notebook battery in my cellar and decided to give it a try. I was able to salvage 8 x 18650 cells. 6 are still on 3.71V, 2 are on 2.1V unfortunately.
After googling I found out that those are 2600mAh cells. Pretty neat!

https://sep.yimg.com/ty/cdn/theshorelinemarket/LG-18650-2600.pdf

Is there a way to revive those cells on 2.1V or are they gone?

I think about a 3s2p battery bank with a built in BMS. Would give me 11.1V for the 817nd. I think thats quite good, I could use a step up converter to boost the voltage if necessary (or if it makes sense).


9
Batteries & Solar / USB Solar charger 5V to 12V
« on: March 19, 2018, 11:57:04 AM »
Hi,

I was wondering if it's possible to use a 5V 2Amps solar charger to charge 12-14V batteries if using a step up converter. I own an Anker 14W solar charger with two usb ports, apparently they can deliver 1Amps each. Looking at those 12V portable solar chargers, they are way over my budget. Somewhere I read that you should charge batteries with 10% of their Ah specs. So let's assume I get a 12V / 7Ah SLAB and using a step up converter, I should charge it with 800mAh.

So, taking the real power of my solar charger, which is not 14W rather 10W (5V x 2Amps) I could deliver
P = U x I => I = P / U => I = 10W / 14V = 0.710A of charging current with 14 Volts assuming the stepup converter has no significant loss.

Is that realistically possible?

Another approach would be to see if the panels are delivering 5V or rather 12V and then transformed to 5V. Or, combining the two USB outputs to one giving me 2Amps at a time and increasing the charging current. I really like the idea of charging my batteries when in the field, but the 12V portable solar panels are really over my budget.

Regards,
CP

10
Radio Reviews, Questions and Comments. / Yaesu 817 vs 857 / 5W vs 100W
« on: March 02, 2018, 08:48:52 AM »
I want to get an all in one radio as soon I get my license.
I like that 817 a lot, its small and great for backpacking and camping obviously. Also, the small current drain is really appreciated. The only thing I am worried about is the 5W of power.
Hows the practical experience using 5W? Can you reach distant stations easily or is it really dependent on the atmospheric conditions?
Does the additional 95W make a huge difference that justify hauling double the weight and size on the radio + 1 x 2-3kg battery in the backpack?
I also read somewhere the 817 has a built in antenna tuner and the 857 doesnt.
Because I will most probably buy only one radio I dont want to regret my decision so I am asking on practical experience.

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