Search found 306 matches

by VK3AUU
Wed May 08, 2019 7:59 am
Forum: Towers, Masts & Transmission Lines
Topic: Radiation Pattern
Replies: 3
Views: 931

Re: Radiation Pattern

It probably wont make much difference.
Suck it and see.
by VK3AUU
Fri Aug 26, 2016 7:33 am
Forum: General Discussion
Topic: What's on your Workbench?
Replies: 603
Views: 58355

Re: What's on your Workbench?

I recently acquired a 432 MHz amplifier with a single 4CX250B, originally built by VK3ZL. It is generally well constructed, bu the power transformer is hopelessly inadequate. It has 550 volt a side output with a bridge rectifier system which produces 1500 volts DC on standby, but that drops to 1350 ...
by VK3AUU
Wed Jul 20, 2016 1:43 pm
Forum: Transceivers, Transmitters & Receivers
Topic: Please Mr ICOM I would like a IC-910 replacement
Replies: 19
Views: 2190

Re: Please Mr ICOM I would like a IC-910 replacement

If what I heard at Gippstech is any guide, they should give away any ideas of DV. Most of us like to be able to recognize the voice of the person we are in contact with.
David
by VK3AUU
Sat Jul 02, 2016 6:42 am
Forum: Transceivers, Transmitters & Receivers
Topic: ACITRON SSB-400
Replies: 20
Views: 2514

Re: ACITRON SSB-400

As far as I Know, Ken VK2AKK is still around. I spoke to him on 40 metres not too long ago. He has all the guff on the rig in question. It ran a QQE06/40 in the final. As I recall, it ran around 1000 volts on the final and it had some sort of pulsed arrangement to time up which produced corona at th...
by VK3AUU
Sat Jun 25, 2016 6:33 am
Forum: LF, MF, HF
Topic: 40 meter rotatable dipole questions
Replies: 42
Views: 5618

Re: 40 meter rotatable dipole questions

The problem with almost any sort of dipole on 40 metres at a height of only 10 metres is that it isn't going to be very directional and there are no decent nulls to cancel out unwanted qrm. A 2 element close spaced delta loop on a 7 metre long boom has a 20 db null off the side and 8.5 db back to fr...
by VK3AUU
Fri Jun 24, 2016 8:34 pm
Forum: LF, MF, HF
Topic: 40 meter rotatable dipole questions
Replies: 42
Views: 5618

Re: 40 meter rotatable dipole questions

Height is the most important thing if you want to get as low a radiation angle as possible. For a full size 40 metre dipole. At a height of 16 metres, which is as high as a fully extended Nally tower with the supplied tube out the top, the maximum broadside gain of about 4.4 dbd will still be at aro...
by VK3AUU
Mon Jun 13, 2016 9:23 am
Forum: FM, Repeaters, D-STAR
Topic: No more repeaters
Replies: 16
Views: 1581

Re: No more repeaters

Before repeaters, VHF operators built beams. Some of us still do. The WIA seems to still think that VHF is only line of sight. I routinely work VK3EJ in Cobram from my hole in the ground in Warragul using SSB without enhanced conditions. Distance is 250 Km. Most of the repeaters around the country j...
by VK3AUU
Thu May 12, 2016 7:38 am
Forum: FM, Repeaters, D-STAR
Topic: VK3RGL 2M Repeater
Replies: 7
Views: 693

Re: VK3RGL 2M Repeater

Take a small beam and use SSB and you might be surprised at how much further you will get.

Good luck,

David
by VK3AUU
Sun Mar 06, 2016 4:59 am
Forum: WSPR
Topic: Suitability of an IC-706 on 2m WSPR
Replies: 6
Views: 710

Re: Suitability of an IC-706 on 2m WSPR

I agree with Steve, but they are easy enough to GPS lock but a small muffin fan helps to keep the drift down a bit.Suck it and see
David
VK3AUU
by VK3AUU
Sat Feb 27, 2016 3:51 pm
Forum: 1296, Microwaves and Opto
Topic: Catalyst about Mobile Telephones
Replies: 28
Views: 3105

Re: Catalyst about Mobile Telephones

I am heartened by the number of intelligent replies and disappointed by those who dismiss the subject out of hand without any attempt at reasoned analysis. As has been pointed out, there is a lot of anecdotal evidence out there, and while it might not be scientific, it does give grounds to be cautio...
by VK3AUU
Sat Feb 27, 2016 2:10 am
Forum: 1296, Microwaves and Opto
Topic: Catalyst about Mobile Telephones
Replies: 28
Views: 3105

Re: Catalyst about Mobile Telephones

We had all this damage control from the tobacco industry when they were vociferously casting doubt on the evidence. The telecommunication industry is the largest industry in the world, twice as large as "Big Pharma" and they are starting to run scared as the evidence is stacking up against them. Dav...
by VK3AUU
Fri Feb 26, 2016 1:18 pm
Forum: 1296, Microwaves and Opto
Topic: Catalyst about Mobile Telephones
Replies: 28
Views: 3105

Re: Catalyst about Mobile Telephones

Some more references to support the Argument. http://www.ncbi.nlm.nih.gov/pubmed/25738972 http://www.ncbi.nlm.nih.gov/pubmed/26556835 https://au.search.yahoo.com/search?p=Low+intensity+microwave+radiation+induced+oxidative+stress%2C+inflammatory+response+and+DNA+damage+in+rat+brain+%28Oct.+2015%29&e...
by VK3AUU
Fri Feb 26, 2016 11:30 am
Forum: 1296, Microwaves and Opto
Topic: Catalyst about Mobile Telephones
Replies: 28
Views: 3105

Re: Catalyst about Mobile Telephones

You should also read the feedback on the Media watch web page.
David
VK3AUU
by VK3AUU
Fri Feb 26, 2016 11:22 am
Forum: 1296, Microwaves and Opto
Topic: Catalyst about Mobile Telephones
Replies: 28
Views: 3105

Re: Catalyst about Mobile Telephones

Did you actually listen to the whole of Dr Davis's lecture.
David
VK3AUU
by VK3AUU
Fri Feb 26, 2016 7:40 am
Forum: 1296, Microwaves and Opto
Topic: Catalyst about Mobile Telephones
Replies: 28
Views: 3105

Catalyst about Mobile Telephones

Those cynics out there who think there is no problem should watch this lecture by Dr Davis. She has been researching this field for a long time. http://www.eng.unimelb.edu.au/engage/events/lectures/davis-2015#sthash.G0Hp1w84.dpuf Take particular notice of the Chinese lady with the Iphone in her bra,...
by VK3AUU
Tue Feb 23, 2016 2:03 pm
Forum: 1296, Microwaves and Opto
Topic: Normal yagi vs loop yagi on 23cm
Replies: 8
Views: 1408

Re: Normal yagi vs loop yagi on 23cm

I would agree with Steve. Once you get above about 20 elements, the gain is largely dependent on the length of the boom, So a 6M long boom would give the same gain whether yagi or loop. That being said, dimensions get a bit more critical on the higher frequencies and although the DL6WU design may no...
by VK3AUU
Wed Dec 23, 2015 7:12 am
Forum: Regulatory, Licencing & Exams
Topic: 60m allocation and EIRP
Replies: 29
Views: 2496

Re: 60m allocation and EIRP

Looks like some people are still getting their licenses out of a Weeties box.

David
by VK3AUU
Sat Nov 21, 2015 4:50 am
Forum: Regulatory, Licencing & Exams
Topic: 60m allocation and EIRP
Replies: 29
Views: 2496

Re: 60m allocation and EIRP

The Yanks just have 4 spot frequencies allocated according to my Flex 1500.
Approx 5.300, 5.346, 5.357 and 5.371. We might get the same deal, although not necessarily those spots so we will have to Tx on a different freq to what we receive on.
David
by VK3AUU
Wed Oct 14, 2015 12:03 pm
Forum: Regulatory, Licencing & Exams
Topic: Exam / Licence Price & Young People ..
Replies: 160
Views: 10092

Re: Exam / Licence Price & Young People ..

The 10 watt limit is also much more practical using digital modes, One only has to look at the results on WSPR.
My little Flex 1500 SDR at 5 watts out is proof of that.
David