The ramblings of 2E0ISK

Gallery back online

Sorry to anyone trying to access the gallery over Easter.
The site has been migrated to a shiny new server and there where some issues.

Do let me know by emailing 2e0isk AT mr-badgerDOT co DOT uk if anything is broken.

Remote shack live

Well, the new shack is now in the bedroom with the old laptop.
Only thing there is if I am downstairs I can't play radio...
I can now, thanks to HRD and IP-Sound voip software.
Now I can operate from my living room via the PC.

Now to set up possible internet access.

First state side PSK31 Contact

Well, I am pleased with myself tonight. I managed to battle through the qrm on 40m and have a short qso with Bryan W4HLD.

Ironically, the G5RV Half has perfomed better in the loft than when it was outside at my old house!
Also nice to see 12w gets out there even through roof tiles.

Seems Richard 2E0GYD did a grand job on installing it for me.

Digital Modes up and running

Well after much re installing of Windows 98 on my trusty Fujitsu Lifebook P166, I set up MMSSTV on 2M successfully and also had my first PSK31 QSO from years, had to dig out a really old version of HRD that works in '98.

I had a short but sweet QSO with Alois OK1HAI on 40m at about 1.30am GMT.
Running 12watts into my G5RV Half.

Thanks to Richard 2E0GYD and Mark M3LXS for helping to install my antennas this past Sunday in my loft.

Hopefully I can get some more action on the digital modes now I am set up.

73 for now.
2E0ISK.

Back on air!

Yes, after 5 years off the air I have, all be it a temporary shack, in place and antennas in the loft.
I hope to get the laptop up to SSTV and PSK Operations.
Will probably be doing test transmissions of SSTV on 2m in the very near future.

Look forward to catching up with some old callsigns and new ones alike.

73
Keith.
2E0ISK.

Winterhill DXperdition September 17th 2006

Yes its official. The party is formed and there was much rejoicing.
Myself 2E0ISK, Rick 2E0GYD, Neal M3NCD and Mark M3LXS are all going to be working VHF/UHF 2 and 4 meters and 70cm via various antennas ZL special 9 element beams and a 19 element ZL 2m boomer.

We may work HF bands but the main focus being VHF/UHF.

We will be working various modes including FM and USB.

More things may be announced closer to the date.

Check out Howards site.

Hi all one of our customers at work is Howard G4CCH he hosts his website with us. Check it out here he has an excellent setup for moonbounce and his dish is something else.

Impressive stuff there Howard.

73
Keith
2E0ISK

Up Up and Away!!!

The Biggest of all the projects took place on Sunday.
Thanks to the installation skills of M3LXS and 2E0GYD my trusty Watson 50 took to the skies.

See pictures here

When asked what he thought Mark M3LXS said 'booming mate booming' :-)

Check out my fellow hams sites

I am now hosting a select few sites for hams who I am good friends with. Please check out their sites (many are not yet in progress):

2E0GYD's Site
M3LXS's Site
M3MQA's Site

Again thanks goes to 34SP.com for hosting my site.

73
2E0ISK
Keith

New to Amateur Radio?

This area is aimed at those new to Amateur Radio or those interested in finding out more.

I am based in Warrington Cheshire. Alot of the information listed in this section will refer to localised clubs etc but this information for your area can be found at the RSGB website.

The local radio club that I am a member of is WARC (Warrington Amateur Radio Club).

To take a look at WARC's website click here.

Keep an eye on this section as I will be writing up new things as I go along.

The westflex is in place

At last I installed some good coax and straight away can hear the difference. Obviously areas I cannot see I cannot hear but those crackly distant regular stations are nice and clean now and I can do well with my 12W linear coming into Runcorn cleanly.

The next step is to pop the antenna on the chimney and get it our of the loft to see how much difference that will make.

73
Keith
2E0ISK

Rig Stand

Another quick project thanks to Michael from the FT-817 yahoo group. He doesn't give his callsign but I saw the way he utilised a soldering iron stand and I did the same. Just the cheap plastic stand with folding metal a few dabs of epoxy resin to hold it on in case you should want to prize is off at a later date. It makes opening the battery compartment much easier ad well as providing a great portable pop out stand.

To see pictures click here.

73
Keith 2E0ISK

Purchase westflex coax and re position 2m antenna

Ok so after a chat with my local friend M3LXS (Mark)its agreed with his kind offer of assistance we will get my antenna on the chimney and replace the coax which currently has a 4dB loss and is not doing me any favours.
Not sure when we will embark on this but its in the pipeline as the next big job.

Slow Scan Television

Slow Scan Television was originally developed by Copthorne Macdonald VE1BFL.

Nowadays it is very easy to use slow scan thanks to easy interfacing between computers and the various software now available to encode and decode SSTV pictures.

More to follow.

Redundant Digital File Transfer and Ham Digital Radio Mondiale

You can find DSSTV (Digital Slow Scan Television) usually on the SSTV (Slow Scan Television) Calling frequency of 144.500mhz in the local area of Warrington and the Northwest of England.

G2ARV and M0JGM along with many other regulars can be found using the Digitrx software using either of the RDFT or HAM DRM modes.

A little about the creator of RDFT:

Indiana resident Barry Sanderson, KB9VAK, is being named as recipient of the Technical Excellence Award for the development of a multi-channel, multiphase modulation scheme known as Redundant Digital File Transfer (RDFT). Not only did Barry 'do the math' but he also wrote the core software routines that allow RDFT to run on personal computers using sound card DSP capabilities. This allows error-free transmission of computer files via standard amateur radio equipment. This technology has been proven very powerful in the area of digital slow-scan television.

A little about DRM:

For those who don't know much about it Digital Radio Mondiale, DRM™ for short, is a method of broadcasting on AM radio using digital signals rather than analogue - it's like listening to an audio stream on the Internet, but broadcast on medium or shortwave radio rather than via the net.

In addition to potentially crystal-clear reception, DRM™ signals can also carry multimedia information in addition to the audio signal, or to carry multiple program streams on one signal:

Used mainly on the HF bands it is also used on 2m with much success.

PY4ZBZ
The HamDRM carriers uses OFDM: ortogonal frequency division multiplex.
The modulated carriers are overlapping in frequency domain and are
modulated in QAM (amplitude and phase).
In the current state of RDFT, the transmission of a file needs three
separate operations : Coding, Recording (of the transmission) and Decoding,
and this increases the total time of transmittin/receiving.
In HamDRM, a file is codified and transmitted simultaneously.
And it is decoded at the same time in that is received. There is only a
small delay between the end of the transmission and the reception
(some seconds).
To transmit a file needs no more separate coding and decoding as in RDFT.
Just load the file (if not to big), or use Jp2 converter for adjust the
picture file a suitable size in bytes.
The file is divided in blocks (RDFT) or segments (HamDRM).
The size of segments depends on the mode particularities.
The Mode A is faster than Mode B but it doesn't support negative effects
caused by multi-path propagation as Mode B, which is more robust.
The QAM modulation can be in 4 or 16 or 64 vectors or symbols.
64 QAM is much faster but needs a very good signal to noise ratio (SNR),
or a high quality channel.
4 QAM is the slowest but it supports more noise, or smaller SNR.
Interleaving consists of changing the natural symbols sequence.
If long (2 seconds), it allows better error correction with slow fading,
but it causes a little larger delay in the reception.
Short interleaving = 400 ms.
The occupied band width BW for the HamDRM signal can be set to 2,3 or
2,5 kHz. The smallest is a little slower and it should be used if the
SSB TX/RX equipments filters are to narrow or have not a flat
transfer function.
The DC frequency simply refers to the inferior limit of BW, and also
should be chosen in agreement with the equipments filters.
The amount of instances is the number of times that a file is transmitted
during one transmission. More than 1 instance allows that if during the
reception of the first instance some segments were not received, they
will probably be received during the second or third instance,
correcting the received file.
Leadin is just a extra time of initial transmission so that the receiver
can have time to synchronize correctly.
BSR is an adapted system from BBR of DIGTRX and allows to do a request
to send only for the missing segments of a received file.