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[IRCA] Connecting External FM Antennas to the Grundig G8
Hello All,
The unanimous praise of DXers for the breakthrough FM performance of the
new Grundig G8 (and its Tecsun PL-300WT clone) has inspired a related
interest in Ultralight FM-DXing, and the connection of effective external FM
antennas to the models.
Although the G8 and PL-300WT perform remarkably well with just their stock
22" whip antennas, hard core FM-DXers are eager to connect their monster
Yagis and Quads to these DSP-enhanced radios, and discover what the units
can do with "real" antennas. Although the G8 and PL-300WT pocket radios have
no external antenna provisions, Tecsun's full-sized DSP portable, the
CR-1100, does have an external FM antenna connector, and provides a few clues as
to how a fanatic "Dark Side" DXer would go about transforming the G8 into
a dream FM-DXing machine.
The CR-1100 is a unique AM-FM full-sized portable, which uses the same
Silicon Labs DSP chip as the G8 and PL-300WT. Designed for great audio
quality, the CR-1100's DSP chip is apparently programmed for a wider selectivity
setting than that of the Ultralight siblings, resulting in more local
splatter on both AM and FM. Despite this, the CR-1100 has its own FM external
antenna connector on the back panel, a standard video-cable type female
connector such as those used for cable TV signals. The CR-1100's brief English
manual mentions nothing about this connector, but the Chinese manual
instructs the user to connect a "50 ohm" FM antenna-- despite the type of connector
used (which is certainly not designed for 50 ohm antennas).
Disassembly of the CR-1100 revealed that this "FM connector" was nothing
more than an unshielded 6" connection to the same circuit board point as the
whip antenna's 5" unshielded connection, making the "50 ohm" instruction
pretty irrelevant. Serious communication receivers and amateur radio
transmitters use shielded cable between external antenna connectors and circuit
board points, with the cable's impedance matching that of the external
antenna cables used. Perhaps this is too much to expect in a consumer radio like
the CR-1100, or the related Ultralights. But for a fanatic FM-DXer, the
ultimate solution would be to install such a shielded, impedance-matched cable
(and connector) to the radio used, which would match the impedance of the
external, high-gain FM antenna used for DXing.
For the 95% of DXers who would not care to do this, simple clip-on antenna
systems (like those described by Gil Stacy and others) can provide a lot
of FM-DXing excitement with the G8. My own system uses a full-wave FM loop
on a 50' tower (with rotation capability) having one lead clipped on to the
G8's collapsed whip antenna, and the other lead connected to the radio's
ground (through the battery connector's negative spring). This simple system
receives stations on almost every FM channel here in the "isolated" NW part
of the country, with many British Columbia and Oregon stations booming in
(in addition to those from my home state of Washington). For those new to
FM-DXing, elevation is a key advantage for FM antennas, much more so than
for MW systems. If you take your G8 to a local hilltop, you will probably be
amazed at the FM-DXing performance increase (and in the process, become
hooked on FM-DXing like the rest of us :>)
Experimentation is continuing on connecting directional FM antennas to the
G8, such as the 2 element Cubical Quad models mentioned previously. Some
type of hand-held portable FM-DXing center would be an exciting summer
doldrum project, in my opinion. In summary, the fantastic FM performance of the
G8 and PL-300WT may well be the equivalent of the inspiring AM performance
of the SRF-59 in late 2007, which kicked off the original AM-Ultralight
radio boom. For those of you still on the fence, summer is the best season to
make your move!
73, Gary DeBock (in Puyallup, WA)
**************Summer concert season is here! Find your favorite artists on
tour at TourTracker.com.
(http://www.tourtracker.com/?ncid=emlcntusmusi00000006)
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