Wednesday, April 11, 2018

RFI from Foxtel IQ2 STB's on 10m & 6m bands

I noticed hearing modulated signals across 29 MHz band and 52-53 MHz bands when scanning the FM segments from time to time, not clean carriers but data  modulated carriers appearing then disappearing.  By accident, I just happening to hear this occurring one day and by chance doors were open in the house where I could see through doorways to the TV set where the XYL was flicking through Foxtel channels.  OMG, the modulation on the signal varying as channels are being changed, here was the culprit, our Foxtel IQ2 STB (set-top-box).

I got out the Uniden handheld scanner and did some sniffing around the  STB, but no, it seems to be radiating from the LED flat panel TV,  turned power off to the TV but noise still radiating, unplug power cable from TV and noise still there, unplug HDMI cable to Foxtel STB, then RFI signal drops off drastically.

Sniff closer to Foxtel box, very strong signal from the ethernet RJ45 cable and the HDMI cable.  Remove both cables and noise almost non-existant.  sniff the power cord at the rear of Foxtel STB and noise still very low,  plugin the HDMI and ethernet cables one at a time, pretty equally as strong.
I noticed it detected noise on 2m band too, but much lower levels than that of 10m and 6m bands.

Outcome, the Foxtel box itself not radiating but very bad when HDMI cable plugged into a LED flat panel TV, as it using the TV as a RFI antenna.  As a secondary source of RFI it using the Ethernet RJ45 cable as a nice antenna too. I think from memory the IQ2 box made by Pace.

Solution, grabbed my box of various  sized ferrite clipon cores, added 7mm ID and 9mm ID cores on the power, RJ-45 and HDMI cables, closest to the rear of the Foxtel IQ2 box, this suppressed the RFI  sufficiently, in terms of 10m and 6m bands, could now only receive RFI up to about 1 metre from the STB, whereas my  transceiver antenna could hear it from 20 metres away.   I also tried clamping some ferrite cores over the two coax leads running to the satellite dish LNA but that made absolutely no difference, so RFI not radiating back out via coaxes, that I could see.

Thursday, March 29, 2018

new 23cm beacon gone live - VK2RSF 1296.414 MHz Nimatabel

a new 23cm beacon has gone live today,  VK2RSF 1296.414 MHz Nimatabel at grid QF43QL, to compliment the existing two beacons on 144.414 MHz and 432.414 MHz

Tuesday, March 27, 2018

GippsTech 2018 now offically dated - 7th & 8th July 2018

I can see the GippsTech team doing a call for papers for GippsTech 2018 now.
To be held 7th and 8th July,   with Friday night dinner at Morwell Pub.

GippsTech 2018 conference

re-post from the VK-microwave@yahoogroups.com forum VK3 Microwave QSO Party

Hi Folks,

Just  a reminder that the VK3 Microwave QSO  Party is just a week away!
The event will be held on Easter Monday 2018, April 2, between the
hours 1000 and 1200 E.A.S.T. 

Bands: 1296 MHz, 2.4 GHz and 3.398GHz

Liaison Frequencies: 144.180 MHz USB, 146.500MHz FM simplex and
147.000MHz FM (VK3RGL repeater).

Please consider using the "Contest Radar" website to alert others to
your QTH portable or otherwise.

Calling Frequencies: xxxx.150 Mhz USB, xxxx.225 MHz JT4f (or FT8?)

You can use the time to test a new portable location, evaluate a new
rig or antenna, swap a picture on SSTV, try a digital mode or just have
FUN!

I look forward to working you all.

73's Rob VK3MQ


VK-microwave@yahoogroups.com

microwave activity on vklogger

I keep seeing these guys getting on microwave bands regularly, see them on vklogger every couple weeks at least. Good to see some activity.


VKLOGGER.com

John Moyle Field Day 2018

I actually went portable for John Moyle Field Day this year,  held across Saturday 17th March and Sunday 18th March, I operated just for the 6 hour session on the Saturday.
I had just over half a dozen contacts, not that I was not really trying hard, as I was also testing equipment, checking for beacons and trying a couple sites, helping a few people get some contacts, get some fresh mountain air.

I operated from two spots, QF56cm, near Zig Zag Railway at Clarence, I had a look at a few spots around, before settling on one site at approx 1150m ASL, nice clear mountain top, low level scrub, it was actually discovered by some friends Geoff VK2AVR and Dom VK2JNA, who had stopped  by when I was operating at a nearby location for a 23 on 23 Microwave Day last year.

After a couple hours, I was not having much luck with making some contacts to some specific people, so I packed up and moved to Mt Lambie QF46xm, it is about 1350m ASL, from here I could actually make some successful contacts.

I'll get all this documented on my website with more photos and map details soon.
The first pic at QF56cm,  the 2nd pic at QF46xm.







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