Search found 1042 matches

by VK2OMD
Wed Aug 20, 2014 12:55 pm
Forum: WSPR
Topic: WSPR has restored my faith in AR
Replies: 24
Views: 8713

Re: WSPR has restored my faith in AR

VK2AVR, I expect that you know I take offence at people falsely representing that I have said something that I didn't, and your post could be taken as intended to cause offence. I did not say what you claimed I said in the following quote, they are your words entirely and a fraud. WSPR sucks The peo...
by VK2OMD
Wed Aug 20, 2014 8:27 am
Forum: WSPR
Topic: WSPR has restored my faith in AR
Replies: 24
Views: 8713

Re: WSPR has restored my faith in AR

VK4DU wrote:But seriously, yes, I know it has shortcomings, but it is interesting nevertheless.

It is AR, afterall....
Yes, yes, it is interesting and worth exploring... just for the understanding if nothing else.

Owen

PS:, love your portrait... you have changed since we last met!
by VK2OMD
Wed Aug 20, 2014 7:34 am
Forum: WSPR
Topic: WSPR has restored my faith in AR
Replies: 24
Views: 8713

Re: WSPR has restored my faith in AR

I have often looked at the Hans Summers kit, but am holding out to see if they ever develop a WSPR tansceiver along the same lines. That would be more than double the fun of just a transmitter/beacon. See my comment above about attic dipoles, tx only, either intentionally or effectively as a result...
by VK2OMD
Wed Aug 20, 2014 7:32 am
Forum: WSPR
Topic: WSPR has restored my faith in AR
Replies: 24
Views: 8713

Re: WSPR has restored my faith in AR

After a mate told me of his experiments with WSPR, I decided to give it a shot myself. This cynical radio professional is impressed. Mighty impressed. ... I also experimented with WSPR, both on air and extensive data mining of my own data, and all data. I was particularly interested in evaluating i...
by VK2OMD
Mon Aug 18, 2014 11:45 am
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

Tree savers are also used for hammock camping. Can see how bushcraft and AR is coming together! :thumbup: It might not be the case for a hammock, but this tree save is placed OVER the bough from ground level, and the halyard to raise the antenna passes through the rings, not over the bough where it...
by VK2OMD
Mon Aug 18, 2014 10:57 am
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

Interestingly, DX-Wire is claiming their 1.5mm UL wire is capable of handling 1500W in full sized antenna installations with AR usage. With various margins factored in, even going up to 100W should be quite safe. Ya gotta learn to treat ALL promotional material as BS until you can satisfy yourself ...
by VK2OMD
Mon Aug 18, 2014 9:11 am
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

I don't know where you guys are getting some of your wire prices from. Stripping down a three core cable is labour intensive, and may result in injury if you are not very careful with a knife. Last time I bought a roll of 2.5mm^2 7 strand building wire (< 3 years ago), it cost less than $40. Jaycar ...
by VK2OMD
Sun Aug 17, 2014 5:49 pm
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

VK3BQ wrote:You need some unicorn dx wire. Seriously :))
...
Hehe, you can tell the BS products, tinned copper is a give away!

(It has higher RF resistance than copper, but it features in most of the super stranded super flexible super DX magic wires.)

Owen
by VK2OMD
Sun Aug 17, 2014 6:30 am
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

Read that carbon being a conductor, a current will be induced and in turn affect the RF radiation pattern and efficiency. Not sure if it's significant or relevant if the CF pole is used just as a hanger with a stand-off distance. You stated earlier that your intention was to support an Inverted V d...
by VK2OMD
Sat Aug 16, 2014 9:21 pm
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

VK4TI said:
VK2OMD wrote:Ok. Just read somewhere about the 90 deg angle for an inverted V. Sounds like I'll need to get a black squid pole for some night time stealth. Time to visit that fishing store.

For the record, this is a misrepresentation, I said no such thing.

Owen
by VK2OMD
Sat Aug 16, 2014 7:13 pm
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

You are putting words into my mouth Barry, can you learn to edit posts so you don't wrongly attribute stuff... especially when it is patently nonsense.

Owen
by VK2OMD
Sat Aug 16, 2014 2:15 pm
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

VK2FABS wrote:Ok. Just read somewhere about the 90 deg angle for an inverted V. Sounds like I'll need to get a black squid pole for some night time stealth. Time to visit that fishing store.
The source most folk use is a store down at Blakehurst, he apparently has quite a range at good prices.

Owen
by VK2OMD
Sat Aug 16, 2014 1:58 pm
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

Working out the geometries on an inverted V 1/2 wave dipole for 40M using a centre squid pole support and I note that a 7m centre support would give it perfect 90 deg angle at the apex. Here are two questions. 1) How critical is that 90 degrees vertex angle? 2) Should a 9 or 10m pole be better for ...
by VK2OMD
Sat Aug 16, 2014 6:37 am
Forum: General Discussion
Topic: What's on your Workbench?
Replies: 646
Views: 106535

An open squelch DCD for MFJ-1270B

My OSDCD prototype under test in a MFJ-1270B: MFJ1270B-OSDCD-Proto.jpg The TNC normally derives Data Carrier Detect (DCD) from its modem chip, usually a broadband energy detector is used. DCD is usend to enable decoding of incoming Receive Data (RD), and to block transmission whilst the channel is b...
by VK2OMD
Fri Aug 15, 2014 8:07 am
Forum: Satellites & Balloons
Topic: PS-16 PICO Balloon Melbourne-Adelaide
Replies: 58
Views: 2972

Re: PS-16 PICO balloon MELBOURNE-ADELAIDE

A good modem chip can yield BER better than 1e-4 given S/N of about 8dB. So if you take your average FM receiver with sensitivity of say -120dBm for 12dB SINAD, say -124dBm for 8dB S/N. (A modem may incorporate filtering to improve that S/N figure.) External noise will probably raise the noise floo...
by VK2OMD
Thu Aug 14, 2014 11:37 am
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Chameleon vertical whip HF - 1.8-54MHz

Came across another compact portable vertical whip antenna system - Chameleon CHA Hybrid-micro + CHA Mil Whip + CHA Mil Whip Ext. Good for 1.8-54MHz and weighs less than 3lb. Not cheap when all three components are combined. http://chameleonantenna.com/PORTABLE%20ANTENNA/CHA%20HYBRID-MICRO/Chameleo...
by VK2OMD
Wed Aug 13, 2014 9:22 am
Forum: Satellites & Balloons
Topic: PS-16 PICO Balloon Melbourne-Adelaide
Replies: 58
Views: 2972

Re: PS-16 PICO balloon MELBOURNE-ADELAIDE

Has anyone done a signal strength require when using APRS.....LOS is not always equal to getting the required strength to be able to decode APRS . A good modem chip can yield BER better than 1e-4 given S/N of about 8dB. So if you take your average FM receiver with sensitivity of say -120dBm for 12d...
by VK2OMD
Tue Aug 12, 2014 5:30 pm
Forum: General Discussion
Topic: What's on your Workbench?
Replies: 646
Views: 106535

An open squelch DCD for TNC-2

OsdcdPrototype.jpg
by VK2OMD
Sat Aug 09, 2014 4:26 pm
Forum: LF, MF, HF
Topic: Antenna opinions and suggestions (started with Tak-tenna)
Replies: 172
Views: 13693

Re: Tak-tenna - Opinions and additional suggestions

These QRP end fed thingys are really popular, but you might ask why no one uses them at 1kW. If I have read the video properly, the primary of the transformer is 3t on a FT50-43 core. Screenshot - 09_08_2014 , 16_14_49.png Above is calculation of the impedance of the primary winding. This can give u...
by VK2OMD
Fri Aug 08, 2014 11:35 am
Forum: Regulatory, Licencing & Exams
Topic: Are hams allowed to repair or modify mains-powered equipment
Replies: 44
Views: 13217

Re: Are hams allowed to repair or modify mains-powered equip

VK2MUS wrote:Owen
I fully understand the argument that foundation operators should upgrade or die.
To be clear, I did not say or imply that, nor is that my opinion.

The outcome of the reform is that anyone is entitled to 'park' at any licence level indefinitely, there are no sunset clauses.

Owen