The Worldwide TV-FM DX Association Website
DIY LOG YAGI FOR FM
Let's face it. Commercially made FM antennas are hard to find, and those you can find cost money...more money than most of us want to spend.
If you can't buy one, build one yourself. Here are plans for a good performing log-yagi with good f/b ratio and gain of around 7-8db with a length of about 96". It was made from plans at K6STI's website but those plans have been removed and replaced with updated versions of this model. But you can find the plans for this antenna here.
You can now download the 2009 Emisoras de FM by Jim Thomas in three parts: MEXICO, CENTRAL AMERICA and CARIBBEAN areas. You can also download the complete 100 page 2010 Emisoras de FM. This publication is no longer in print. Also remember that up-to-date listings for Mexican FM stations can be found at our WTFDA US/CANADA/MEXICO FM Station database.
WTFDA presents a randomly selected group of articles for your reading pleasure. These may change from time to time so if you find something you enjoy, be sure to grab it.
Posted by Admin | February 25,2014
SDR stands for Software Defined Radio and SDRs have become very popular with DXers. An SDR usually consists of a radio in a black box that attaches to your computer with a USB cable and is tuned with software on your computer monitor. AM Dxers have been using them for a few years. A few SDRs that come to mind are the SDR-IQ, Perseus and Winradio Excalibur. Many AM DXers use these models.
FM DXers have been left out in the cold until now. The word on the street is that there's an SDR that's the equal of a modified Yamaha T85 tuner. This SDR is called the Elad FDM-S2. It covers longwave through 150mhz. Tests have shown it to be excellent for FM DXing with no overload in locations close to FM transmitters.
To read more about it go to http://ecom.eladit.com/ELAD-FDM-S2
There's another SDR under development that also covers FM. It's called AirSpy and can display a good chunk of the FM spectrum using SDR# software. It also should be more affordable than the Elad SDR
To read more about Airspy, go to http://airspy.com/
Everybody wants to know what types of equipment TV DXers use in their hobby for best results. We've asked around for info on the best CECBs (set top boxes) and DTVs. Top DTV Dxers agree that the manual tuning of RF channels with up/down buttons is a must! Unfortunately, most DTVs don't allow it. A few allow for direct entry of RF channels but most allow for channel scanning only, which makes DTV DXing harder than it should be. Channel scans take time, sometimes minutes, and during the time it takes to do a scan, a DX station could have decoded and dropped out without you ever knowing it. DXing by channel scans should be avoided if at all possible.
So, considering that manual tuning is critical for success, here is our list of DTVs and set top boxes with manual tuning. We also include those known to have direct entry tuning (enter *2* then *1* for channel 21). Direct entry tuning is not as desirable as full manual tuning, but is still better than a DTV offering only channel scans.)
SET TOP BOXES/DTVs with MANUAL TUNING
1. Insignia NS-DXA1 CECB
2. Zenith DTT-901 CECB
3. Zinwell ZAT-970A CECB
4. Coby DTV-102 CECB
5. Sansonic FT300-A (the feature is called "Antenna Level") CECB
6. Silicon Dust HDHR3 & HDHR-US (network computer controlled tuners)
7. LG 32LG30 32" DTV (9/2009), 24" LG24LN451B, 42" LG42LN5300, and probably the entire line of LG DTVs. For an example of how LG DTVs tune manually, go here. One WTFDA member purchased a LG DTV recently, compared its sensitivity to an Insignia converter box, and then decided to retire the Insignia box.
Direct Entry (of RF channels) Boxes & DTVs
1. Magnavox/Philco CECB
2. DigitalStream CECB
3. Toshiba 26" 26C100U1 DTV
4. Toshiba 26LV610U (2009) DTV
5. Panasonic 501 DTV
6. Sylvania 6427GFF DTV
7. Philips 19" 19PFL3504D/F7 (2009)
And there you have it. If you know of any others, let us know and we'll add them to the list. (Note: we do not guarantee this list to be 100% correct and cannot be held responsible for any inaccurate data).
The new TDT transition policy no longer includes a phased-out switch by locality or coverage zone for the various analog shutoffs and December 31, 2015 will be the only deadline.
According to the authorities, now it will be by coverage zones and according to the delivery of TV sets on behalf of the SCT that the shutoffs will be realized before the deadline.
As such, the IFT opened a new public comment period for the shutoff, as the previous one was modified and the second transitory paragraph of the accord published in the DOF (Mexico's federal register) on July 2, 2004 and last modified on May 7 of this year was abrogated.
Article 6 indicates that the concessionaires and permittees of television stations are obligated to perform all the investments and installations necessary to convert to digital, and the IFT will oversee the due completion of this obligation.
The new policy includes the obligation of television operators to solicit additional digital channels as is established in the new Telecommunications law.
Transitory article 9 indicates that the IFT must receive all of the legal and technical required items related to operating the additional channel within 60 days from when the IFT notifies them (the concessionaires).
Article 13 establishes that the concessionaires and permittees must assure the continuity of broadcasting service - in other words, guarantee the adequate transmissions of digital signals.
They must replicate at least the area of coverage of the analog transmission, but not beyond the coverage zone (licensed area to serve - these are different things, and localities outside the area but inside the zone can solicit shadow channels).
Article 16 indicates that the Institute will inform the population about the analog shutoff in mass media, flyers, informative sessions and an Internet portal.
Once the analog shutoff occurs, the concessionaires and permittees will only be able to use one channel to broadcast digitally; the other channel will no longer be conceded or permitted and Ifetel will be able to make use of it.
This info obtained from a post on the WTFDA Forums (forums.wtfda.org).
WTFDA is the only Radio hobby club in North America that caters to the TV and FM DXer, as well as the amateur radio operator who looks for DX on 6 meters. The term "DX" means "distant reception", and those who "DX" look for weak, distant radio and television signals, with an eye to logging as many of these distant signals as possible or obtaining the most distant reception of a given station. TV and FM signals normally only travel 50 to 100 miles out from their transmitters. DXers love to push the reception boundaries of stations by hundreds or thousands of miles by using their skills, better antennas and equipment, and knowing when conditions are ripe for it.