Search found 159 matches

by VK2ZIW
Tue Mar 19, 2019 2:00 pm
Forum: FM, Repeaters, D-STAR
Topic: Repeaters NW NSW
Replies: 7
Views: 5633

Re: Repeaters NW NSW

A Full Duplex repeater makes for significant infrastructure needs, both 6m and 2m. Really good receiver, good cavity set (expensive and bulky). Would a Half Duplex (store and re-transmit) system make life much much easier. One transceiver, no duplexer, single antenna. And, a major benefit, one could...
by VK2ZIW
Sun Mar 17, 2019 6:33 am
Forum: Digital Modes Miscellaneous
Topic: FreeDV on Thursday!!
Replies: 34
Views: 14614

Re: FreeDV on Thursday!!

Looking for a portable solution: Have a look at "SmallDV", an implementation for a Pi with one audio USB dongle. Note, ONE audio dongle with mono mic input so audio switching needs to be done externally, a relay. I've found an available stereo mic input dongle, the Creative Sound Blaster ...
by VK2ZIW
Sun Mar 17, 2019 6:23 am
Forum: Digital Modes Miscellaneous
Topic: FreeDV on Thursday!!
Replies: 34
Views: 14614

Re: FreeDV on Thursday!!

Summer is over, so back on 7177 KHz LSB Example activity: bytes date, time, file 960 Feb 22 20:21 7177/2019-02-22-17_20_53_to_radio.700C 1280 Feb 22 20:25 7177/2019-02-22-17_24_56_to_radio.700C Nothing since. These files are the Codec2 700C data format. The decoded (.WAV) files are on: www.unixservi...
by VK2ZIW
Fri Dec 21, 2018 6:02 am
Forum: Arduino, Picaxe, Raspberry Pi, and variants
Topic: Pi Software and Hardware issues, Linux
Replies: 7
Views: 5798

Re: Pi Software and Hardware issues, Linux

Then came kernel 4.15.X and the introduction of Power Management. Laptop and tablet power management has introduced many driver changes. NOT ALL GOOD. Ubuntu 16.04 with kernel 4.15.0-39-generic on my PC, ASRock Q1900-ITX repeatedly just stops until I unload the GUI and boot up, just command line. s...
by VK2ZIW
Tue Dec 11, 2018 5:14 pm
Forum: FT8
Topic: FT8 version 2 is coming
Replies: 38
Views: 16807

Re: FT8 version 2 is coming

Has anyone compiled and run it up on a Raspberry Pi yet?

Alan VK2ZIW, running LOW POWER here, less than a 10W computer.
by VK2ZIW
Tue Dec 11, 2018 6:21 am
Forum: 144 & 432 MHz
Topic: Hybrid Rings
Replies: 1
Views: 4539

Re: Hybrid Rings

Hi Mark, Two radios (VHF or UHF) on the one antenna. My advice, don't do it!! Get a rig with scanning capability to monitor several frequencies. I use a VX-5R hand-held to monitor 6m from a 5/8 vertical. I use BNC connectors as they are fast to change, one rig to another. Mark, I looked for your ema...
by VK2ZIW
Tue Dec 11, 2018 5:44 am
Forum: Digital Modes Miscellaneous
Topic: FreeDV on Thursday!!
Replies: 34
Views: 14614

Re: FreeDV on Thursday!!

Hi all, I've modified David's FreeBeacon code to be a repeater, store and retransmit. I started in mid July 2018 but had problems with the Linux system crashing, running only a few hours. (now fixed, Nov '18) The Thursday nights on 7177 have obviously died out as I received nothing, nothing except t...
by VK2ZIW
Tue Dec 11, 2018 5:25 am
Forum: FT8
Topic: FT8 2 meters
Replies: 6
Views: 6697

Re: FT8 2 meters

How about trying Digital Voice to replace SSB? With Low BitRate codecs and modems now available, download the app or source: www.freedv.org I've modified David Rowe's FreeBeacon code to be a store and forward repeater. It's running now on 14.153MHz, mode 700D. Put my callsign in the text to trigger ...
by VK2ZIW
Wed May 18, 2016 8:29 pm
Forum: 1296, Microwaves and Opto
Topic: Cavity Back Dish feeds for 3.4 GHz
Replies: 3
Views: 1461

Re: Cavity Back Dish feeds for 3.4 GHz

How can we make the feed a crossed dipoles arrangement for circular polarization?

My thought, loop dipoles formed with 1/4" hard line or coax loli-pop style. Feed opposite the stem.
Cavity will have to be supported by non metallic something.

Alan VK2ZIW
by VK2ZIW
Wed May 18, 2016 8:07 pm
Forum: E.M.E.
Topic: Building an EME station pictorial
Replies: 29
Views: 11431

Re: Building an EME station pictorial

Conveyor belt gearboxes, I have one, 40:1 with 35mm thru shaft. Now available on eBay, not so two years ago. http://www.ebay.com.au/itm/Worm-Gearbox-Type-40-1-40-Ratio-40-Reduction-/231274729746?hash=item35d90c5112:g:Aj0AAOSwDk5Ttfha 200mm x 200mm x 100mm worm gearboxes are < $200AU from China Zheji...
by VK2ZIW
Wed May 18, 2016 7:41 pm
Forum: FM, Repeaters, D-STAR
Topic: Australian DMR repeater network
Replies: 42
Views: 19281

Re: Australian DMR repeater network

Check out the MMDVM and MMDVMHost software and the Yaesu DR-1X.
http://xilfy.com/v/Ty3ugvDtqB8

Should work with any repeater really. All that is needed is to bypass any audio filtering.

Alan VK2ZIW
by VK2ZIW
Wed May 18, 2016 1:03 pm
Forum: Digital Modes Miscellaneous
Topic: DMR, P25, D-Star and Fusion using MMDVM
Replies: 1
Views: 4074

Re: DMR, P25, D-Star and Fusion using MMDVM

On my Banana Pi with Fedora 23 I'm having problems generating the "bin" load file for the Arduino DUE. Fedora Linux comes with the package "arduino" Ver 1.6.4. The errors I get: IO.cpp.o: In function `ADC_Handler': IO.cpp:87: undefined reference to `io' core.a(main.cpp.o): In fun...
by VK2ZIW
Wed May 18, 2016 12:48 pm
Forum: Digital Modes Miscellaneous
Topic: DMR, P25, D-Star and Fusion using MMDVM
Replies: 1
Views: 4074

DMR, P25, D-Star and Fusion using MMDVM

Hi, Has anyone got any experience with MMDVM modems or MMDVMHost here in OZ yet? Adrian VK4TUX is doing a lot with software development, (Yahoo group MMDVM) WICEN NSW is seriously looking at and using DMR as hiring lots of HandHelds is both quick and affordable. We provide the repeater. So, the chal...
by VK2ZIW
Thu May 12, 2016 6:34 pm
Forum: Digital Modes Miscellaneous
Topic: FreeDV on Thursday!!
Replies: 34
Views: 14614

Re: FreeDV on Thursday!!

We have myself and Hil VK2IUW transmitting now...
by VK2ZIW
Thu May 12, 2016 6:23 pm
Forum: Digital Modes Miscellaneous
Topic: FreeDV on Thursday!!
Replies: 34
Views: 14614

Re: FreeDV on Thursday!!

It's 6:25 and nobody heard here in Emu Plains
by VK2ZIW
Wed May 11, 2016 10:05 pm
Forum: 144 & 432 MHz
Topic: V360CL 5A NEC TRPA
Replies: 16
Views: 9480

Re: V360CL 5A NEC TRPA

What do I do with the V600DH ?
It's full of circulators, one between every stage!!
175MHz or there abouts.
Also 4x 100W 28V pager (148.025MHz) PAs?
by VK2ZIW
Wed May 11, 2016 7:16 am
Forum: FM, Repeaters, D-STAR
Topic: Australian DMR repeater network
Replies: 42
Views: 19281

Re: Australian DMR repeater network

Don't forget WICEN. Message passing over a 'secure' channel. Also, two channels over one repeater. Availability of lots of hand-helds for a search and rescue, something Fusion or D-Star will never match. We are all in the learning phase here. Will a MMDVM based network build and overtake the DMR-MAR...
by VK2ZIW
Wed May 11, 2016 6:57 am
Forum: FM, Repeaters, D-STAR
Topic: 10m repeater for VK7
Replies: 3
Views: 4575

Re: 10m repeater for VK7

Would a "parrot" repeater for 6m and 10m be acceptable? With 6m in particular, a band opening often happens when only 'you' are around. So, you hear the repeater tail and ident, but never know what your audio is like. Our Dural 6m repeater for instance gets two regular QSOs per day. That's...
by VK2ZIW
Wed May 11, 2016 6:46 am
Forum: FM, Repeaters, D-STAR
Topic: VK5RBV 146.825 replaced with Yaesu DR-1X
Replies: 5
Views: 4871

Re: VK5RBV 146.825 replaced with Yaesu DR-1X

DR-1X, AC fail indication.

Our DR-1X (purchased April 2016) does not have the AC power supply. Only DC.

So, how do we make it run low power and somehow indicate it's on battery with
no mains or solar power?

Alan VK2ZIW, maintainer of BMARC (Blue Mts.) repeaters.
by VK2ZIW
Mon May 02, 2016 10:11 pm
Forum: EMC, Interference
Topic: Quarter wave stub bandpass plot
Replies: 12
Views: 7349

Re: Quarter wave stub bandpass plot

Sorry, but RG6 is THE WORST coax to use, except for satellite TV. The alfoil does not connect to the braid. Inside an "F" connector there is no solid connection to the alfoil inner shield. Period. The anodizing oxide coat on the alfoil is way too good an insulator. Yes, the braid gets crim...