RadCom April 2024, Vol. 100, No. 4

Propagation 88 April 2024 NOTICES TO READERS. © Radio Society of Great Britain, 2023. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the Radio Society of Great Britain. ERRORS AND OMISSIONS. Whilst the Radio Society of Great Britain (the publisher) takes all reasonable care in the production of RadCom , we can accept no responsibility for errors, inaccuracies or omissions contained within the magazine or any subsequent loss arising from any use thereof. Reliance placed on the contents of RadCom is at the reader’s own risk. We urge any reader to take all precautions appropriate to avoid any loss or damage to equipment and ensure the personal safety of themselves and others when using material contained in RadCom . It should be also noted that patent, copyright protection or usage restrictions may exist in relation to any items within this magazine. The RSGB does not accept any responsibility for failing to identify any such patents, copyright, protections or regulations regarding their use. Readers are also reminded that the use of radio transmission and reception equipment (including scanning) is subject to licensing conditions. The use of any equipment should comply will all local regulations and the erection of external antennas may be subject to local authority planning regulations. ADVERTISEMENTS. Although RSGB staff and the staff of Danby Advertising (its Advertising Agent) take reasonable precautions to protect the interests of readers by ensuring as far as practicable that advertisements in the pages of RadCom are bona fide, the magazine and its publisher, the RSGB, cannot accept any undertaking in respect of claims made by advertisers, whether these advertisements are printed as part of the magazine, or are in the form of inserts. Under no circumstances will the magazine accept liability for non-receipt of goods ordered, late delivery, or faults in manufacture. Legal remedies are available in respect of some of these circumstances, and readers who have complaints should address them to the advertiser or should consult a local Trading Standards Office, or a Citizens’ Advice Bureau, or their own solicitors. The publishers make no representation, express or implied, that equipment advertised conforms with any legal requirements of the Electro Magnetic Compatibility Regulations 1992 or subsequent legislation. Readers should note that prices advertised may not be accurate due to tax changes or currency exchange rate fluctuations. R S G B HF F-Layer Propagation Predictions for April 2024 Compiled by Gwyn Williams, G4FKH (Utilising the ITURHFProp prediction engine. The sunspot number for April 2024 is 104). 3.5MHz 7.0MHz 10.1MHz 14.0MHz 18.1MHz 21.0MHz 24.9MHz 28.0MHz Time 000001111122 000001111122 000001111122 000001111122 000001111122 000001111122 000001111122 000001111122 (UTC) 024680246802 024680246802 024680246802 024680246802 024680246802 024680246802 024680246802 024680246802 ***Europe Moscow 973cefeb3799 886322245888 877554556887 347666667754 124666666422 a13466665311 ba12333331ab cb1122222abb ***Asia Yakutsk 32abcbb12333 432222233444 443323334444 ba3333334221 .ea23321abcd ..da12abdee. ...cbace.... ...edce..... Tokyo ........25.. .....fb2571e bceeb124563a aaaa12344521 cba1222223ab edba1211a1cd .fdbaaabdcf. ..ecbbcdfe.. Singapore ........366c ......e36774 be...e156664 abcdca356542 cbbba134431a ecbaa12331bd .ebba1122bf. ..dbbaa1ae.. Hyderabad 2e.....d4666 4ae...c36777 42bddc146666 111aaa345553 db211234531b .ea1223441ce ..caa1122cf. ..dcbaa1ae.. Tel Aviv 96a.....2799 875befd15788 876321246788 746544456677 316555556454 ac3555554131 de1223332cab eeba1111aece ***Oceania Wellington ............ ...edcba2... eed122234f.f aaa333334abb aaa2333231aa bbb1222111ab cdca11abbabc efecabcddcdd Well(NZ)(LP) .b4......f.. 157.....e41a 467d..eca543 4561bbaa1554 3342aaaab443 2131aabbd333 1b1abcce.121 bdbbcde..b1b Perth ........355. ......e36662 c....f145654 acefea244433 bbbcb12221a1 cbbba211abdb fdbaa1acde.f .ebba1ce.... Sydney ........35.. ......b367c. e...fb35662d bcdda244552b bbbb123333ab cbba122211bc ecba111abcee .ecbaabcee.. Melbourne (LP) ..b......... ea43........ 1255af.....c 23452bccbdc1 21242abbaba1 1aa21abbbb11 bcc1abcccbab dffbbddddcac Honolulu ..1......... f151be...... b24321adffec aa12321abbba ceda2211aaab e..b11aaaabc ...fbbcbbbdf ....ddeccdf. Honolulu (LP) ............ ............ .e.....da... cacf..e12bdd aaacccb131ab aaaabba131aa bbaaaa1131aa bcaaa11a2abb W. Samoa ..f......... ..31cef..... eb3321ab.... ba233321cccc bcc12221abbb ceea1211aabc f..daaababcd ...fcbbcbcdf ***Africa Mauritius 6.......2666 7d.....b6777 61f...f36766 31bcdca46554 aaaaaa145421 ccaaa123421b .fbaa1122ace ..cbaaa11cf. Johannesburg 66......d476 77......5787 55c....b6776 221bddb26665 cc21aa135543 ff1111235431 ..a11223421c ..b1112231bf Ibadan 887a....1788 77731bb14777 777421124777 656532345666 314544445643 ab2544455521 dfb3444452ac f.d122333ade Nairobi 66b....e4676 6621ccb25776 66421a135676 334322246665 ab3432345651 de143334553c ..b43344521f ..d2234431b. Canary Islands 9963f...c589 88862ab13788 888653345788 777755556777 434666666774 323666666643 211466666422 1a1234646311 ***S. America Buenos Aires 666.......e3 777b.....e46 6662f....156 5443adeec354 21211abb1332 abaa1aaa1321 dfeda1a112ac f..fbaaa11cf Rio de Janeiro 776.......36 777d.....477 7662....f567 5553bcdca565 32321aa12543 1a1121112432 bdcb1111231b d.ed111122bd Lima 666........2 7772......36 6554b....d45 33341bddc144 1ba21aaaa121 ced1a1aa111b ...ccaaaaabe ...edbbbabe. Caracas 7773c.....26 77741cf.fb46 66652bcdc156 544432aaa254 1aa13322232a bddb232223ac f..ebaaa1ac. ....cbbbabf. ***N. America Guatemala 566c.......2 6664b.....b5 55542ceffc25 322421bbb134 acc112111221 dffba111121b ...edaaaaabe ....fbbbabd. New Orleans 6673b.....e3 66642bdceda4 55553abacb24 311212111122 bddcd121221b e..efba221be .....dbaabe. .....fdccd.. Washington DC 77752d...d15 677642aaa136 666542222245 211243222343 cedca333332a f..fc22334ad ....faa111c. .....ccbabe. Quebec 6774adeeeb25 67752aa11236 546431122345 1aaa22233343 efeeb133441b ....eb1122be .....dcbaae. .....fddcc.. Anchorage 22321abcba11 333332212233 344333223333 bba211113331 f.ebdcccbaad ...effeeddcf ..........f. ............ Vancouver 1351cf.fe.fd 24531bdaaba1 2243bcb12a12 cdbbeec1212a ..f...fcaabd .......dcbd. ........ee.. ............ San Francisco 156c........ 4663acf...da 444321bcdba2 1a11aaaaa111 ceecddba11ab f..f.fcba1bd ......ecbbd. .......eddf. San Fran (LP) ............ ............ .......e.... dcf..ebaceff bacdcba21bcc aabbbba21abb bbaaaba22aab bbaaabb21abb Rad Com Key: Figures and letters represent approximate S-meter readings. S9 (9) represents 50µV RMS in the 50 ohm receiver input impedance, down by factors of 4 in power (6dB) through the numbers to S1 (1), and then continued sequentially below that using letters a to f. Thus, a represents a signal which is 6dB lower than S1, and so on. The colours represent expected circuit reliability, Black 0-30%, Blue 30-60%, and Red 60-100%. No signal is expected where a ‘.’ is shown. The predictions use the ITURHFProp ionospheric model, assume 100W Tx power into a dipole antenna, and a matched dipole antenna at the Rx. See Predicting Propagation ( RadCom September 2020 page 37) for instructions. See also the PSC web page for propagation predictions programs, https://rsgb.org/main/technical/propagation/on-line-propagation-tools/, which can be tailored to your own setup .