Most recent measured "mark" QRGs underlined:
|Tout door/kHz||10 m BCN||4 m BCN||6 cm BCN||3 cm BCN|
||28 228.024||70 032.805||5760.935||10 368.935|
Measured frequencies were referenced to GPSDO
Equipment used: MT8802A locked to GPSDO reference.
Try your DSP FFT display on these at great ranges!
OH5TEN&RBG Beacons' ODXes
|OH5TEN 10 m bcn: KM3T 6359 km||OH5TEN 6 cm bcn: OH2AXH 92 km|
|OH5TEN 3 cm bcn: OH2AXH 92 km|
|OH5RBG 4 m bcn: CT1HZE 3606 km|
|Ham , BC & air frequencies in KP30:||Link to: Six and Ten Reporting Club|
|114.599 MHz 200 W ERP UTTI VOR, AM
CW ID: "UTT"+voice
105.700 MHz 30 kW ERP Radio Nova RDS: 6209 __NOVA__
102.700 MHz 30 kW ERP The Voice RDS: 62AB _VOICE__
99.500 MHz 30 kW ERP FSR Mix RDS: YLE_X3M_ YLE_VEGA
96.900 MHz 30 kW ERP YLE Radio Suomi 6203 YLESUOMI
92.800 MHz 30 kW ERP YLE X RDS: 6202 __YLEX__
88.500 MHz 30 kW ERP YLE Radio 1 RDS: 6201 YLE_YKSI
70.033 MHz 15 W ERP
28.228 MHz 4 W ERP
Send reception reports to DX-Summit
We also QSL (OH5TEN OH5RBG via OH5IY )
"Corrected" Tropospheric Path Loss = TX ERP [in dBm] + RX Ant. Gain [dB] - RX feed line loss [in dB, often negligible] - antenna height loss [in dB, see graph below] - -145 dBm [CW RX sensitivity level] - band noise above 290 K [in dB, from upper graph per your location's man-made noise level]
It is expected your RX system Noise Figure is substantially below 3 dB! (RX k curve)
Using the calculated Corrected Tropospheric Path Loss value, you are able to determine the approximate maximum range (CW mode) from upper graph (signal received 50% of time).
Note: the "Corrected" Path loss here is used include effects that reduce RX S/N ratio specially on 50 and 28 MHz due to higher noise levels on those bands to get the true range and not just pure path loss. If you need only the path loss for shorter range to estimate signal level when S/N is not an issue, do not correct for band noise!
Note: Range can be reduced by lower TX and/or RX antenna's height, terrain and other obstructions and by factors such as poor RX system Noise Figure, higher local noise level which to some degree can be corrected using the graphs.
OH5RBG's 70 MHz beacon's ground wave coverage. Computed signal
strengths (S-units) with 8.5 dBd RX antenna at 25 m above average ground
level with unobstructed take-off, S 1 = 0.2 uV (-121 dBm) @ RX input.
The 70 MHz beacon was built during fall of 2009 with latest technology: USB-controlled synthesizer, PIC-based PC-configurable keyer and MMIC driving the FET PA. The basic scheme works for all bands from 28 to 70 MHz with just modifications to driver LPF and PA stage coils and capacitors - the single-ended FET PA is narrow-band type. Using the 175 MHz application sheet for RD06HVF1 FET, the beacon can be built for 144 MHz operation also. 432 MHz model would need different version for the synthesizer chip - the faster LVDS reaching up to 910 MHz.
The first built beacon module was for 40 MHz, but uncertain and troublesome licencing caused a rebuild to 70 MHz (took some 2 h) which has been a ham band in Finland since 4th Nov. 2009. The enclosure holds the 70 MHz beacon TX module with G4JNT keyer and a 4.5 A SMPSU. FET PA feeds some 5 W to a horizontally polarized low-gain (7 dBi) antenna (Aerial AV1462-70) beaming Az. 232° (SW for sporadic-E propagation) mounted on a cellular tower on a hilltop 131 m + 8 m ASL and delivering 15 W of ERP.
In detail, the synthesizer, which is configurable for any QRG from 3.5
to 260 MHz in 1 Hz steps (and for exact FSK shift) via the USB connection,
delivers a 0 dBm (square wave) fed via 2- section LPF to ERA-5SM MMIC amplifier.
G4JNT RS-232-configurable PIC-keyer keys the SDR-Kits USB-synthesizer.
The +16 dBm drive feeds a low-cost SWR tolerant Mitsubishi PA FET delivering
5 W RF-output. The output is filtered with several LPF stages, one for
UHF for added attenuation on cellular frequencies (harmonics are attenuated
by 119 dBc on 900 MHz UMTS band). Total currrent is monitored with a 2
A analog panel meter. The antenna output circuit has a 230 V gas-disharge
tube, 2 kV series capacitor and antenna connector & case bonded to
site ground bar.
|10-2010->10-2015||28.228 MHz||50 MHz||70 MHz||432 MHz||1296 MHz||2320 MHz||5760 MHz||10368 MHz|
|TX Pout||+37 dBm,
|Refl. coeff, VSWR||pi-match||-26.5 dB,
1/1.37 or better
1/2.3 or better
|Pant, ERP||4 W,
The TX is the ex. commercial Multitone TA8 TX modified to FSK
with G4JNT keyer. With 1 dB cable lossses and mid-line LC-match (50
to 71-j20 ohms), some 4 W RF is fed to a slanted-dipole with horizontal
polarisation at 9 m AGL with maximas to 250 deg. and 70 deg. and shallow
side minimas not more than -13 dB. The ID "OH5TEN KP30HV" is send
every 45 seconds and in between a 30 second carrier. The frequency
stability is unknow so far, but the XTAL has the QH40A heater bundled along
with some thermal insulation. The ambient temperature varies from +20 C
to +8 C annually.
OH5TEN's 28.228 MHz beacon's ground wave coverage. Computed
signal strengths (S-units) as received with a 6 dBd antenna at 25 m AGL.
CW keyed (G4JNT keyers) Si570 local oscillators (120 and 108 MHz) with QH40A heaters, are indoors at room temperature. The 12 V DC power from 4 A SMPSU is fed to ODU via Lo coaxial cables with bias-Ts, each ODU drawing about 1 A current. The mutipliers are from DB6NT kits (5.7 GHz modified link TX unit and a 10 GHz BCN TX unit). 5.7 GHz PA is commercial Walkera PA5801 and the 10 GHz PA is from Dirk Fisher Elektronik.
ODU is build in an ex. Allgon 900 MHz base station panel enclosing 1 m long home made waveguide slot antennas from std aluminium profiles milled with hand tools for each band, delivering horizontal polarisation, very flat beams and 13 dBd and 16 dBd of gain illuminating 100° wide sectors centered at WSW with 5° of up-tilt to climb over an adjacent hill and treetops there. Because of the tilt, the beacons works better on rainscatter propagation than on tropo. Except for the opening towards WSW, treecover is generally dense except for some narrow gaps to S and SSW. The 10 GHz coverage map is modified to account for the trees blocking the takeoff.
|OH5IY||measured Prx (@input)||Ga , line loss||hant|
|28.228 MHz @ QRB 10 m, TET dipole||+10.8 dBm (w. 5W) (HF ant 80°, VHF array: 160°)||+0 dBd, 1.0 dB||9 m|
|70 MHz , LPDA||-55.6 dBm||+2.5 dBd, 2.5 dB||10 m|
|10 GHz, TV SAT LNB||+3.2 dBm at 335 m az 226° (low tilt 0.5° - just for the test)||-, horn&LNB gain undefined||2 m|
|10 GHz, TV SAT LNB||-17 dBm at 335 m az 226° (med. tilt 3.5°)||-, horn&LNB gain undefined||2 m|
|10 GHz, TV SAT LNB||-25.7 dBm at 335 m az 226° (high tilt 5°)||-, horn&LNB gain undefined||2 m|
OH5ADB received in KP30HV on 144.455 827 MHz with 19.7 dBd antenna and
1.4 dB feed losses at -117 dBm.