Announcements
Saturday, January 02nd, 2010 | Author: admin

Quality not Quantity! Mon, 08 Feb 2010 09:46:41 GMT posted by Watty

Since launch in early October 2009 we have been growing slowly but now have over 100 Members.

Most of you are very technical people, a high percentage are Radio Amateurs or people in the TV/Satellite trade or involved with ISPs / Telecoms.

Don’t be shy about contributing Articles and ideas in the Forums. We can help "polish" them up and copy in your User name to the special Article section. Unlike some sites YOU retain full copyright, only releasing to us a non-exclusive right to "publish" on this site. If we make any profit ever (unlikely!) we will share some percentage of it with Article Authors according to degree of contribution and Site impact.

Because the Articles section displays uploaded images full size it limits view of them to Registered members (free). This saves bandwidth and reduces content scrapers and embedded linking. Ordinary Registered members can’t post direct into Articles, but good Articles posted in Forums will be "promoted". Also the Member posting will get "promoted" also. Subscribers (i.e. People that give money to help running costs) get automatic Article posting rights and anyone with "Journeyman" (applies to Females also :) ) rank and higher has Article posting rights.

Drop me a PM or post here if you would like to see new Forums, specific articles, change in your user rank or any other change.

Mike (aka Watty, aka EI9FEB, formerly GI8JTR), Site Admin.

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Tech News
Tuesday, November 03rd, 2009 | Author: admin

Updating from the Tech News & Media forum

Germany to give DVB-H a second chance? Mon, 25 Jan 2010 19:01:57 GMT posted by byte

Taken from BBTVN:

Quote:

The German state media authorities hope to reach a decision on giving DVB-H mobile TV a second chance by the middle of March. A condition for opening a new tender for a DVB-H licence is that there will be “a relevant interest of the market” for a new 10-year concession.

“We have always stressed that only concrete interest can open the door for a restart of DVB-H. Interested parties must have reached agreements with the network operators, broadcasters and mobile operators. They must clearly indicate how the planned cooperation will be realised and what will be the economic viability, ” said Thomas Langheinrich, chairman of the Commission for approval and oversight (ZAK), in a statement. “Because a system that is not economically viable, can not help to develop diversity.”

Ever since the Mobile 3.0 consortium handed back its DVB-H licence in the autumn of 2008, a special working group of the regional media authorities has explored a possible rebirth of a DVB-H service with potential candidates and other market players. The ZAK now hopes to reach a clear decision on the possible future of DVB-H.


http://www.broadbandtvnews.com/2010/…ture-of-dvb-h/


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Broadcast, TV, Radio & Comms.
Tuesday, November 03rd, 2009 | Author: admin

Updating from Broadcast Category

Comments on features of Catpad Sat, 06 Feb 2010 19:46:37 GMT posted by Watty

The handheld speaker mic for FT817 (adapable for any CAT/CIV radio).

see http://www.techtir.ie/forums/showthread.php?t=3355

Comments and Questions about UI and functionality?

(comments on the Electonics/ SW here http://www.techtir.ie/forums/showthread.php?t=3376)

Initial version is for FT817ND, but you can modify for most radios with Cat/CIV (IC706, FT897 etc…)

Current Feature List:

  1. 100 user defined Bands. Remembers current band and previous band,
  2. 200 user memories/channels
  3. — also saves split, CTCSS, DCS, aerial selection, power , preamp/IPO/Atten, start & end TX bleep options etc for every band/memory
  4. Memories / VFOs / Bands and settings don’t use the Radio memories.
  5. DTMF during TX by 0..9 and A..D, # * keys, no other key/menu needed.
  6. Precompose a text message and send via CW(Morse). PSK31 and Packet may be later updates.
  7. — Possible CW decoder with PSK31 and Packet may be later updates.
  8. up to 32 Transverter definitions (to set TX /RX limits and display offest) and actual radio Rx/TX operation limits[1]
  9. Speaker & Microphone built in with VOX operation
  10. Optional RDS and Stereo decoder + headset amp for FM (currently works via 1200 pin on Data I/O port of radio). However this requires changing a capacitor inside the FT817 on the dedicated WBFM 76MHz to 108MHz IF/Detector IC from 20nF to 2nF
  11. Clear large 128 x64 graphics with On, off or autooff backlight. About 8 rows x 21 columns
  12. of text. Three text sizes and Bold.
  13. 16 button DTMF keypad, 4 menu keys and option for 5 way Navipad/nubstick
  14. Direct frequency entry on Receive by 0 ..9 key, no other menu or key needed. Optionally * is a decimal for MHz and # completes entry with 0s as rest of frequency, the end Menu key cancels entry.
  15. Only a bit larger than a large "fist mic"
  16. Might have a built in Real Time clock independent of Radio power
  17. Powered from radio. Battery operation is feasible.
  18. Scanner and Analyser modes can scan across Radio native band edges "jumping gaps". The Scanner / Analyser modes plot graphs of Received signal, Power and Return loss.
  19. Can read Analogue "Band Data" since it must connect to the ACC port.[2]
  20. Backup and Restore of Radio EEPROM (all configuration, Memories, Bands)
  21. Import Radio Memories & Band settings from the EEPROM backup

[1]For example the FT817 appears to have 14 fixed limit bands and one "spare/phantom" band. Actually as far as the aerial is concerned there is All HF, 6M, band II, Air, 2M and UHF. The IPO/NAR/ATT settings are per FT817 logical band.
But there are really actually five bands on an FT817ND:

  1. HF + 6M: 0.1MHz to 56MHz (55.999,990), no gaps, any mode.
  2. WBFM Only (Uses a different IC for IF & Detector): 76 to 108MHz (107.999,990), no TX
  3. AIR (any Mode though): 108 to 137MHz (136.999,990), no TX
  4. VHF, any Mode: 137 to 154MHz (153.999,990)
  5. UHF, any Mode: 420 to 470MHz (469,999,990)

So these go in the "Setup" of the Catpad as real bands/ limits. The User defined bands can cross the limits except on frequency entry or scan the Catpad will jump to nearest real frequency allowed. The 60m / 5MHz channels is just a software setting depends on reading solder blob switch on front panel ONLY on later models but can be changed in EEPROM on earlier models. I’m not sure if it uses the 80m or 40m band filters, judging by the 0.3V per band signal it appears to use the 80m band low pass filters which must block 7MHz and above. 160m band = 0.33V and UHF = 4V.

[2] FT817 miniDIN connectors
The ACC port has the CAT data in/out, Tx Inhibit, ALC (input from linear) and Analogue Band Data output.
The DATA port has NO data on it. It is Transmitter Analogue in = DATA IN, Analogue Receiver out = DATA OUT 1200bps (any mode), PTT, SQueLch and Analogue Receiver Out (only one FM RX mode) = DATA OUT 9600bps. Every mode including simply listening can use 1200bps pin, but ONLY 9600bps FM packet can use the 9600bps pin, and you still need a modem.


Interesting info for SDR Sat, 06 Feb 2010 06:47:59 GMT posted by Watty


New North Cork Club Fri, 05 Feb 2010 21:19:00 GMT posted by Watty

Quote:

Just a Quick note to make you aware of a new Radio Group starting up in the North Cork Area.

We are a small group of Amateur Radio operators and enthusiasts. Membership is open to all with an interest in the group and its commitments to radio awareness in North Cork.

Further info is available via our website http://www.northcorkradiogroup.com

Membership is currently €10.00 per annum, applications and the club constitution are also on our pages.

Regards

Anthony EI3GAB


*******************************
There is also a new Club started recently in Wicklow

See also http://www.irts.ie/cgi/affiliat.cgi for a list of Clubs on this Island.


1.25m Band Fri, 05 Feb 2010 09:43:52 GMT posted by Watty

This is 220Mhz to 225MHz.

Should we campaign for this for Region 1 for Amateur use after Analogue Switch off in Band III (175MHz to 275MHz, RTE1 & RTE2 VHF TV)?

Is any Irish service using it today?
http://en.wikipedia.org/wiki/1.25-meter_band


4M Radio (70MHz) Thu, 04 Feb 2010 18:16:44 GMT posted by Watty

The NI 4m yahoo group seems a little dead :(

I was looking at this:
http://rudius.net/oz2m/70mhz/transverter.htm

it’s very good, but a tad complex and expensive.

I’m designing two solutions:

1) a 145MHz IF converter using a 25MHz Crystal multiplied by x3 to 75MHz.
75MHz + 70Mhz = 145MHz for RX and 145MHz – 75Mhz = 70MHz for TX.
I’ll test LM1496/MC1496, a double balanced diode mixer made from 4x 1N60 diodes and 2x mini-toroids like the ones in TV splitters and SL602 / SL612 Mixer/Osc as three alternatives.

2) Change 7.6MHz crystal and VCO coil on an 8 Euro iTrip to 6MHz crystal and larger coil for FM 70MHz direct TX with a 200mW PA added. Use a 2 Euro AutoScan FM radio with VCO and aerial coil increased for RX.


28°East: Is there a backup plan? Sat, 30 Jan 2010 15:35:36 GMT posted by byte

I’m sure most of have already heard about the seemingly big failure of Eutelsat’s W2 satellite at 16°E this week. Some services were out for a few days.
http://www.broadbandtvnews.com/2010/…n-of-services/

Made me wonder, is there any backups in place should one of the satellites at the 28.2/28.5°E cluster fail?


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