Tuesday, February 6, 2018

2018 Events


Easter Holidays  -  30th March to 2nd April -  going to Central West NSW for portable VHF, UHF and SHF portable.

WIA AGM  - 18th to 20th May  -  up on the Gold Coast QLD, at SeaWorld Conference Centre.

GippsTech Conference (VK3BEZ.org)  - 6th to 8th July at Morwell, VIC.

October Longweekend - 29th Sept to 1st October - going to Central West NSW for portable VHF, UHF and SHF portable.

Monday, December 18, 2017

VK2RCW Repeater Update

an update regarding the  VK2RCW repeaters operating in Central West NSW,
that are owned and manged by the Amateur Radio Central West Group.

The repeaters had been relocated in middle of 2017 to their new location QF46qu, height is around 950m ASL, the two analogue FM repeaters are :
147.200 MHz output and 147.800 MHz input (+600kHz offset)   no ctcss tone required.
439.300 MHz output and 434.300 MHz input (-5MHz offset)  no ctcss tone required

The multi-mode digital repeater 439.975 / 434.975 MHz is off air pending its relocation.

The VK2ACW  30m HF APRS Receive Gateway is also pending relocation.

www.arcwg.org

Thursday, November 9, 2017

vk-172 GPS mouse driver issue for remote timesynching

Dave VK2JDS has done a write up on the vk-172 GPS mouse Windows10  driver issue, which affects  users going remote portable where there is no internet coverage and internet timesynch available, I added the writeup to my webpages.

http://www.qsl.net/vk2kfj/gps_mouse.html

Wednesday, November 8, 2017

PLL boards, Signal Sources etc.

I also bought some cheap PLL Developer boards  to play around with. They suffer from jitter, but  good enough for experimenting with. Also picked up a 4GHz white RF noise source for testing microwave receivers, ie. 1.2GHz, 2.4GHz and 3.4GHz transverters.

http://www.qsl.net/vk2kfj/pll.html

VHF, UHF and SHF wide band LNA's

I bought a few of these cheap wide band LNA's that run off 12v or 5v, with varying Gain and Bandwidths,  at a few bucks each,  they good for playing and experimenting with in terms of weak signal receivers for VHF, UHF and SHF.   Good selection around on Ebay and AliExpress.

http://www.qsl.net/vk2kfj/lna.html

GPSDO - GPS Disciplined Oscillator

I picked up one of these  BG7TBL 10MHz GPSDO units a few months ago to replace a borrowed Rubidium based 10 MHz reference unit.  Again this BG7TBL unit is 10 MHz sine reference, with GPS receiver input to lock it to GPS satellite time signals, so that this box provides NMEA 4800Baud data, plus 10 MHz signal, plus 1PPS signal to drive other devices.  There is even a smaller, lightweight unit available now for portable operation.

http://www.qsl.net/vk2kfj/gpsdo.html

Tuesday, October 31, 2017

GPS info - NMEA serial data and 1pps output

I have added a write up  regarding GPS boards for extracting NMEA serial data for APRS use  and also extra 1pps (1 Pulse Per Second) signal for use with providing GPS locking of 10 MHz Reference signal  (or other Reference frequencies) for providing an accurate and stable source, typically for locking a Local Oscillator source for a microwave transverter kit, or for other transceivers used  for doing weak signal digital modes, such as WSPR and WSJT.

http://www.qsl.net/vk2kfj/gps.html

Monday, August 28, 2017

more 70 MHz (4metre band) info

just some more followup on the WIA band plan submission for a tiny slice of  70-87 MHz segment,  WIA asking for 70.000 to 70.500 MHz,  that 500kHz to play with,  definitely more than adequate in my mind, plenty to experiment with.

Noting what Region1 has for a bandplan, if we could get the same slice here (Region3), then obviously we need to use the same Bandplan as Region1 to be able to work Region1 from Region3 during E's.

https://iaru-r1.org/index.php/spectrum-and-band-plans/vhf/4-meter


70.200 MHz  SSB calling.

70.450 MHz  FM calling ,  using 12.5kHz FM channel spacing.

70. 260 MHz       -  AM calling !!   really ??  that's legacy modes for sure.

70.100 to 70.250     that's 150 kHz for weak signal nodes,   heaps of space.

70.300 to 70.500  FM at 12.5 kHz spacing = 16 channels,    that's plenty of channels !!

I think  70 MHz would be good fun, with ducting, tropo and E's propagation modes.

fingers crossed we get a slice to play with.

http://www.qsl.net/vk2kfj/4metre_70MHz.html

Tuesday, August 22, 2017

Modifications for the TYT TH-9800 FM quad-bander mobile transceiver

These TH-9800  quad band FM transceivers  (a clone of the Yaesu FT-8900 transceiver) have an issue of blowing the transmit driver FET.  I have documented a modification to fix this, as it would be a considerable amount of work to replace the drive FET, or even the PA FET for that matter. Easier to do the mod and run at less output power, better than having a dead tx PA. It basically adding a 8v (7808) regulator into the supply circuit for the Driver FET,  which is fed hot from the 13.8v DC input.

http://www.qsl.net/vk2kfj/th9800.html


Reducing RFI from your vehicle for operating mobile

I have documented the modifications to my 4WD  vehicle that I use for mobile and portable operation. It was only that in past year I have decided to operate HF, whereas in the past I only ever had VHF and UHF equipment, so RFI radiating out and also from within the vehicle was not so much of a problem, but is more so for HF.  My web page includes photos.

http://www.qsl.net/vk2kfj/holden_jackaroo.html