EA6VQ's 144 MHz EME calendar 2021

You could also be interested in the on-line EME calculator and the DX news and calendar database

 EA6VQ's EME WEEKEND CALENDAR - 2021    EA6VQ's EME BEST DAYS - 2021 (DGRD < 2.0 dB)

Weekend
2021

CONDITIONS on 144 MHz

Jan    02-03

Very Good

09-10

Moderate -> Very poor

16-17

Moderate

25-26

Poor
30-31 Very Good -> Good

Feb     06-07

Poor -> Very poor

13-14

Moderate

20-21

Poor -> Very poor

27-28

Very Good -> Good

Mar    06-07

Very poor

13-14

Moderate and New Moon on 13th

20-21

Very poor -> Poor

27-28

Very Good -> Good

Apr     03-04

Very poor

10-11

Moderate and New Moon on 11th

17-18

Very poor -> Poor

24-25

Very Good -> Good
May    01-02 Very poor -> Poor

08-09

Moderate

15-16

Poor -> Moderate

22-23

Good

29-30

Very poor -> Moderate

Jun    05-06

Very Moderate -> Poor

12-13

Poor -> Moderate

19-20

Moderate

26-27

Moderate
Jul    03-04 Poor
10-11 Moderate -> Good and New Moon on 10th
17-18 Moderate
24-25 Moderate
31-01 Poor

Aug    07-08

Good but New Moon on 8th

14-15

Moderate

21-22

Moderate -> Good

28-29

Poor
Sep    04-05 Good
11-12 Moderate -> Poor
18-19 Moderate
25-26 Poor

Oct    02-03

Good

09-10

Moderate -> Very poor

16-17

Moderate

23-24

Poor -> Very poor

30-11

Good
Nov    06-07 Poor -> Very poor
13-14 Moderate
20-21 Poor -> Very poor
27-28 Good

Dec   04-05

Poor -> Very poor and New Moon on 4th

11-12

Moderate

18-19

Poor / Very poor

25-26

Good
        

Days

CONDITIONS on 144 MHz
Jan 1-4 Best DGRD = 1.3 dB on 1st
Jan 28-Feb 1 Best DGRD = 1.2 dB on 28th-30th
Feb 24-28 Best DGRD = 1.1 dB on 25th-27th
Mar 24-28 Best DGRD = 1.1 dB on 25th-27th
Apr 20-24 Best DGRD = 1.3 dB on 22nd-23th
May 18-21 Best DGRD = 1.5 dB on 20th
Jun 14-17 Best DGRD = 1.7 dB on 14th-16th
Jul 11-14 Best DGRD = 1.7 dB on 11th-13th
Aug 8-10 Best DGRD = 1.5 dB on 8th BUT New Moon on 8th
Sep 4-7 Best DGRD = 1.5 dB on 4th-6th BUT New Moon on 6th
Oct 1-5 Best DGRD = 1.5 dB on 2nd-4th
Oct 29-Nov 1 Best DGRD = 1.7 dB on 29th-31st
Nov 25-28 Best DGRD = 1.9 dB on 26th-28th

The best EME conditions occur when:

  1. The Earth-Moon distance is at the absolute minimum and
  2. The Moon is in the coldest sky region (less background noise) along the moon path.

The effect of distance is independent of frequency, but sky temperature decreases with frequency, up to ~1 GHz and then levels out. The EME signal-to-noise ratio, in dB, is DGRDaded, from the minimum, by a factor (DGRD, see below), which varies over hourly, daily, weekly, monthly and yearly time periods. As a guide for the basic weekend EME conditions the present calendar lists the expected conditions based on the DGRDadation (DGRD) value. Factors such as local noise, antenna beam width, side lobes, polarization, etc. can also affect the s/n ratio of moon bounce signals.

Conditions:

Summary of EME conditions as controlled by DGRD at 144 MHz and New Moon. Conditions may be worse, due to ionospheric disturbance, local noise and polarity, but not better than indicated.

In general, 144 MHz DGRD:

Within a day of New Moon (NM), high sun noise can make conditions very bad regardless of the DGRD.

When two different conditions are indicated for the same weekend, it means that they change from the value indicated on the left at Saturday's moonrise to the value indicated on the right at Sunday's moonset.  For instance:

Dec   07-08

Moderate -> Poor

means that on Dec, 7th Moonrise conditions are Moderate and get worse until Dec, 8th Moonset when they are Poor.
 

 
Share: Twitter   Facebook   Home page Site map Radio Sherlock search engine Terms of service  Privacy  Cookies