MX0PHX active on 20m/14MHz 08:00-24:00 UTC from IO92KT @ 200mW with OCFD or dipole

 WSPR - Weak Signal Propagation Reporting

updated occasionally

20m band spots - 8 September to 7 October

from DXplorer SB


7 October
- Off-centre fed dipole in use as main antenna.

5-6 October
- WSPR was 'offline' for a software & hardware upgrade to allow remote control.

8 September to 7 October Summary

Spots show strong diurnal variations on the 20m band with the best conditions being either side of local noon. Conditions between midnight and 0600 UTC are invariably depressed, but with occasional open DX paths across the greyline. Morning and evening greyline conditions vary. All conditions fluctuate according to the degree of solar-induces geomagnetic disturbances that occur.

Seasonal changes are now bringing more, welcome, DX contacts on the higher HF bands.


MX0PHX currently uses a WSPRLite standalone transmitter with a SotaBeams 'power conditioner'.  The WSPR station is currently limited to transmissions on 20m (although a brief trial on 30m was undertaken recently and found to be of little use. Receive capability on 40m and 20m will be added once initial tests have been completed.

Main Antennas
During testing three different types of antenna have been used:

Off-centre fed dipole (similar to 'Carolina Windom'). This multi-band antenna has proved to be consistently the best one to use at the PARC HQ (IO92KT). It is a 21m antenna fed at 13.4m via a 4:1 current balun. The height above ground is 13m at the ends and 10.5m at the feed point (vee configuration). The impedance range across all bands is <65 Ohms, reactance is <10 Ohms and SWR <1:2 except on 18Mhz (1:3.5).

Additional Antennas

Doublet for 30m/10MHz. 15m long (2x 7.5m) and fed with 300 Ohm twin via a G-Whip 4:1 Guanella balun. This antenna is much better than the 20m GP vertical, but much less effective than the OCFD. Impedance is 65 Ohms, reactance 10 Ohms and SWR on 20m is 1:1.4.

20m GP vertical. This comprises a 5.1m wire antenna on a 6m glass fibre pole, with four 5.1m above-ground radials, fed at ground level via a G-Whip 1:1 balun. Impedance is 56 Ohms,0 Ohms reactance and SWR 1:1.1. This antenna did not perform as well as expected despite the apparent efficiency.

Station details

Call sign MX0PHX
Location 12km south of Nottingham, England
IARU Locator IO92KU
National Grid Reference SK 584 301 (WAB SK53)
Post Code  NG11 6QE
WSPR transmitter  WSPRLite (Sotabeams)
Output power 200mW
Usually an Off-Centre Fed Dipole (occ. a 2x 7.5m doublet)
Operated by    

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