Welcome to Tropical band

To most people the phrase "tropical bands" bring a pretty clear picture to mind - a bunch of shirtless guys playing calypso music. But to experienced shortwave DXers those two little words express the most challenging and enjoyable part of the radio hobby. The phrase kindles memories of a DXer's best catches and favorite QSLs, of exotic stations, music and of early morning listening sessions. (Don Moore)
I like the "Tropical band" name for new 60m allocation. (OK1RP)

Effective from 1st Jan 2017 please paper QSL via OM-bureau only.

Monday, January 24, 2011

Solar flux/Sunspot index vs. QSOs logged


as I got some emails regarding the relationship between the Solar flux, Sunspots, A-index and QSOs on LB there I am posting quick analyze from last few weeks...

All green line markers in the chart represents more than 2 QSOs on 60m band and 160m band outside EU in my log. In most cases I worked 5-6 QSOs on the low bands using 100W and my small antennas (base coil loaded half sloper for 160m w/apex 11m and inverted Z dipole w/apex 9m).

All of the good nites corresponding to a bit higher A-index and low Solar flux/Sunspot numbers in the chart.

Any comments from LB DXers are highly welcomed.

73 - Petr, OK1RP

Terrific propagation on 60m this weekend (w03)


so I have to say unfortunatelly that after several trials during last 4 days I still did not worked Texas on Tropical band...

We arranged several skeds with Charles, K5SUL but without success. I realized that the Solar flux and Sunspot numbers were very high compare to last week so I did not expected anything special.

What was interesting this weekend on the 60m band was so directional conditions. After my calling on 5261/FA channel QSX upper channel for USA on Sat nite I got the call from Garry, K4AVC with very nice signal comes from NC. I was delighted to work him and I was a bit confident to make some another one from USA.

I spent 2 hrs on band but I did not worked anybody (few skeds failed) and even I did not received anybody on band. Also on ch5 there was no traffic.

Does anybody met this directional conditions on Tropical band also during high levels of Solar flux and Sunspot indexes?

73 - Petr, OK1RP

Saturday, January 22, 2011

US night on 60m Tropical band...


on 19/1/2011 I listened to my communication receiver (see
Tropical Band DXing by broadcast listeners article overe here on blog) and I realized that there are many stations from USA readable in between 5-6MHz broadcast band. Well it sounds like good propagation to NA tonite which maybe will alow me to work some stations on 60m ham band also. As my antenna is still not the USA killer I have to watch the conditions carefully.

I am sending an eml to few friends active on 60m and going to turn ON my K3 around 22:45z. Starting CQ on FA channel with QSX to ch2...no chance as there is huge QRM from intruder. OK > QSY to ch3 should help. No it's even worse here so I moved to finally ch5. There is no traffic and I am starting to call CQ again on FA split up to ch5.

After few minutes I am recognizing in the noise Pete, N0FW. After several trials we exchanged reports. Not easy so I guess the conditions are not the best but ok lets go to continue call on frequency.

I am getting some calls but I am not able to copy any complete call. YES...Charles, K5SUL is calling me for sure. Callsigns are completed so now we have to get report. Deep and long periods QSB making it hard. Charles did not received my report and I have nothing too. Grrrr I need the Texas on tropical band. After 30mins we are trying it again. Long minutes I am trying to send my report for him (btw sigs improved a bit). Charles completed report for him correctly. I am very nervous as some RTTY local station make me QRM for few seconds. No, not now please. We are trying to repeat the report for me but I am not able to get it correctly. After 40 minutes I scratched the battle. No correct QSO for now. :(

I hear another weak station on ch5 for me. Several trials... Again QRZ > 4? Well number 4 please again? K? recognized in the noise. I am trying all of my antennas (3pcs) but no way...Again please K4??? My correspondent must be dissapointed that I am so deaf! Grrr...again? No, no, no I am not able to copy my frend. Just K4?? but nothing more.

I call CQ again but dissapointed with preview trial I am thinking about QSY to bed.
Just about 00:55z Bob, W4DR is calling me with good sigs. Nice QSO improved my state of mind. New state for WAS60 > very good. Immediatelly after I am called by another station. Lot of noise on channel and intruder with wide spectrum of carriers making me challenge to get the call. I am asking again to call me please. Well number 4 I got but nothing more. Again...K4??? but still deep QSB and lot of noise. After several trials I am trying to use EQ in my K3. I am not experienced and situation is even worse. EQ goes OFF. Please again...K4?C. Well I got K4C?? using DSP NR and playing with Notch filter. After for some seconds signal going up. Yes I got N4CH. it should be "CH". I am sending quickly report and believing that improved signal will sustain few seconds more. OK > I am getting report and it seems that QSO is done. Ufff. I am tired.

On the ch5 calling some UK station the USA. Well but if someone is calling on ch5 it should be for me as there is split operation untill now...I am thinking and asking on FA channel CW QRZ? Yes Gary, K4AVC is calling me with solid signal. We made beautiful QSO and I am working my another US state to WAS60 > NC. Great!

Upss...I have just 3.5hrs for sleeping before my leaving to QRL (50 miles by car to Prague city) as same as 2 nites before. I am so tired and it seems that I will have problem to not sleeping close to test equipment in the lab...:(

I am turning K3 tcvr OFF and going zzzzing. In the morning my son was boggled at my face after waking up. Maybe my face was more or less zombie, hi.

When I arrived to QRL I found eml from Les, K4DY. "Petr I called You several times but finally You did not copy me." :(( I really need better antenna for rx USA I think.

Totals: 4QSOs from OH, VA and NC (4 init callsigns) using 100W and low apex Inverted Z dipole (see on this blog an article about this crazy antenna)

Nothing special just one another nite on the 60m Tropical band...

73 - Petr, OK1RP

LZ - DXCC #12 on 60m


tonite 21/1/11 between 17z-18z on 5260.7kHz on CW I worked LZ2DF. Many stations worked LZ on this band this evenning as LZ2DF had big signal in central EU.

I know that Mike, LZ2DF is very active listener and he is watching this band quite often. His 60m band monitoring activities are focused on the long distance QSOs conditions and multi hops propagation. His lsng reports can be often seen on cluster and his support and contribution help a lot to all of us in band study!

Thank You Mike for Your effort and help,

73 - Petr, OK1RP

Tuesday, January 18, 2011

Turkey - DXCC #11 worked on Tropical band


so after several trials with Atilla, TA4ED we managed QSO tonite on tropical band.

I am really so happy... Atilla was so nice to make QSO on CW with me and allowed me to work > my new one DXCC #11, WAZ60 #4 and WAC60 #3. I know that it is maybe not big DX for some of You but for me TA is very rare on 60m band CW and even I also hunted AS continent on this band for WAC60. Nice!

It was not easy as we tried to make QSO several times during last weeks but we never had success. I heard one time Atilla very weak but he did not copied my pipsqueak signal. As I built new experimental antenna for EU it seems that signal improved. The only problem tonite we had was QRM from some local source. Regarding the new experimental antenna > after few of QSOs with UK stations it sounds like UK killer, hi. I am receiving "+10dB", "339>599+" reports comparing to preview antenna from UK stations. I am happy because the idea was to have an antenna for EU and mainly for UK ragchews.

So many thanks to Atilla for nice CW QSO > very good job my friend!

73 - Petr, OK1RP

Monday, January 17, 2011

UK Military Stations on 60m

Communicating with UK Military Stations

The 5MHz NoV sets a licence condition that for the first time allows UK Amateurs to establish communication with military or military cadet stations. Such stations have an operating procedure that is based upon the four concepts of BREVITY, ACCURACY, SECURITY, and SPEED - or “BASS” for short, thus please respect their operating procedure.

Note that Air Cadet and Sea Cadet stations use M-prefix 3-letter call signs, usually followed by two digits, whilst Army Cadet stations use one or two figure call signs, sometimes followed by a letter. The military stations are not allowed to give their unit name, location, or the operator’s name. It is hoped that they may be allowed some flexibility with respect to QTH locators. Cadet stations may be heard working each other on frequencies close to ours, but it is NOT permitted for amateurs to contact cadets on such frequencies.

Assessment of SINPO

Whilst the traditional RS(T) report can be given at the start of a contact to give the other station some idea of the likely quality of the subsequent contact for the purposes of the experiment, we require a more detailed and follow the ITU recommendation that SINPO reporting is used, as defined in their current document SM.1135.

The S (signal level) report, on a scale of 1 – 5, is effectively an assessment of how well the signal stands out above the background receiver noise. Details of the assessment are given in Table 2 below. Note that we ask that you record a “not heard” as S=1, when it is known that the station is actually transmitting on channel.








Degrading effect of

































Barely audible





If You already heard stations using for example MRN prefixes on 60m and You would like to learn more about then check the link as follows: Fivemegs Experiment

73 - Petr, OK1RP

60m - Tropical band in CT


Anacom authorized few of CT's to operate in 60m band on temporary basis.

Authorized dates: 1st January 2011 to 30st April 2011.
Authorized frequencies: 5371,5 kHz and 5403,5 kHz.
Transmission modes: A1A (CW) and J3E (SSB).

Anacom bandplan

Many thanks to Miguel, CT1IUA for information published on his web and hope to meet more CT's on Tropical band CW...

73 - Petr, OK1RP

60m - Tropical band in F


I was very surprised by receiving the actual 60m band information from France.

Several stations in France are monitoring the Tropical band and spotting even DX's on cluster so I expected that 60m allocation is on the way...

One of the active Tropical pioneers in France is Bernard, F9IE.

"Dear Petr,
So sorry, but France is still not allowed to use 60m band...! I'm listening this band for many years, made cross band 40m qso's especially with N.A. and G's and apllied for a licence 3 years ago and waiting ...!!! So I propose to you a cross band QSO only. Me on 7160 and you 5260 SSB both way is OK at any time. I can monitor, especially at sunset for me what about 17h30z? I heard some OK already working USA ( OK1FBH? ) See U
Best 73, Bernard F9IE / EU-064"

Wow, Bernard asking the permit for 3 years and it seems there is no progress. I already sent the letter to their national authority with the gently question about the current status so I will post the reply if some will arrive.

Bernard, keep fingers crossed to get license for Tropical band soon.

73 - Petr, OK1RP

60m - Tropical band in EA


do You need the Spain country on 60m band? Unfortunatelly it seems that we will have to wait for EA... although I realized that some EA stations monitoring already the band.
I asked Jose, EA1AIW who is active listener on 60m band and there is what I got from him up to actual situation:

"Dear Petr, in my conutry is not possible to transmitt in 60 meters band. I am sorry but I am waiting that we could make QSO in this band but no access yet. Thank for email, good Dx, 73-Jose, EA1AIW"

As there are no news from Spain Telecommunication office we will have to be patient at this moment.

73 - Petr, OK1RP

Sunday, January 16, 2011

Experimental 60m Inv Z dipole for pocket size lots


although the 60m Tropical band is not as low as Top band for example the 1wl is still enough to have troubles with full size antennas.

For all of You with the pocket size lots for antennas there is antenna inspiration > Inverted dipole where the second half of legs are folded to "Z" letter (according to actual space on the garden)

All neccessary information are on the picture so just few comments to installation only:

- higher apex > better results
- shorter folded ends > less compromise and better results
- it's possible to experiment with folding the legs to different directions
- my feed point apex is just 7m and it seems to be low for long distance QSO
- in my QTH this antenna is more noisy than half sloper > ext. RX antenna is a must

I put it up as temporary and experimental piece to check where and how I can put the legs of my dipole on the garden. The changing of the legs and position of the dipole parts incl. the feed point is expected to reach best results for DX...

I will welcome if somebody will be so nice to make PC analyse of this configuration (in MMANA or other s/w) to let me know an idea about current radiation patterns and impedance condition...?

Current data meassured by MFJ-259 - SWR 1.5, Z=30+j4 at 5260kHz but incl. about 20m unknown cable. So data are probably not usable.

Good luck if You will try to put it up also.

73 - Petr, OK1RP

Saturday, January 15, 2011

Short dipole for 60m Tropical Band

By Enrique A. Wembagher, Argentina
HCDX Antenna Special, 1 August 2004

This is an antenna specially calculated for the tropical 60 meter band, with instructions for those who do not possess a lot of space at their locations.

This antenna is a short dipole made up of inductores (L1 /L2) in half of each arm, based with the concept of inductive load.

The dimensions are shown in the figure. The L1/L2 can be built on tubes of PVC; the feeding slope to the radio can be either coax of 50 or 75 ohms.


Antenna: A total of 12 meters of wire, with a diameter of about 2 mm, divided into four sections. Insulators cn be of porcelain or PVC. To fasten the antenna one can use, thread of clothes for the anchorage.

L1/L2: Two tubes of PVC of 5 cm (2 inches) of diameter and approximately 20 cm of longitude. Roll 60 turns of wire of 1.5 mm on each tube, closely wound. A length of 10 meters of wire should be sufficient for each inductor.

The diagram above show the disposition of the antenna with its respective inductors L1/L2.

By Enrique A. Wembagher, Argentina

60m - Tropical band in OZ


According to information from OZ friends the 60m band operation is legal with DTA license.

You need to obtain a special license from the Danish Telecom Agency to be able to operate on 60m. You have to pay an annual fee for the band. This new license allows You to use the entire band from 5250-5450 kHz (VFO based > not channels definned) with even 1 kW and all modes.

Be note that in OZ the 60m licenses are still on a trial basis and time limited by end of 2011.

73 - Petr, OK1RP

Friday, January 14, 2011

Atlantic ocean crossed on 60m - enjoyment with San, K5YY


I finally crossed the Atlantic ocean worked my first QSO with USA ever on 60m band!

San, K5YY from Arkansas was able to read my call and correct report 44 for him around 00z. We used our only allowed channel in OK land > 5260kHz and I qsx to his USB on 5346.5kHz/ch4. Very unforgetable moment for me on 60m tropical band because of several reasons:

1. I am 1st OK station on 60m band for San, K5YY as he reported!

2. San, K5YY is my 1st overseas/non-EU station on 60m band!
3. San, K5YY is my 1st USA station on 60m band!

I used 100W into half sloper (designed for 160m) + receiving Mini Diammond, W2PM loop. Although it is designed for 160m band operation I am satisfied with this loop also on 60m tropical band where this small loop doing good job. Less noise and better s/n.

My hat is going down in face of San, K5YY and his setup on 60m. My signal is pipsqueak on the tropical band because the base loading coil for 160m in the feed point of the half sloper makes big losses on 60m for sure. San informed me that he is using sloper system for RX/TX which means that the performance of this system must be very well. Good job San!

Latest great news from yesterday evening > QSL from San, K5YY arrived! Just 7 days or so from USA to Czech - nice. I am really happy for it as it is my 1st QSL confirming QSO on 60m band at all !!!

Excellent enjoyment on 60m tropical band with You San - thank You!!!

73 - Petr, OK1RP
Tropical band - the
band of 60m pioneers

Thursday, January 13, 2011

60m - Tropical band antennas


if You are looking for antennas suitable for the Tropical band then try to check the link as follows. Maybe it will help You or atleast it will motivate You to build some new antenna to improve Your capability.


73 - Petr, OK1RP

Icom IC-735 on 60m band


maybe it will help to somebody...

Icom IC-735 60m Mod

Disclaimer: Performing this mod will allow an Icom 735 to transmit outside of the Amateur bands. Perform this mod at your own risk. We performed this mod on our Icom 735 and it worked for us. However, your experience may vary. Personal Database Applications, Inc. is not responsible for any rules violations or damage to your radio that may result.

The mod for gen/cov tx for the IC-735 involves removing D33 and D34 from the PLL unit board. You'll have to lift the PA module up to do this and locate the diodes close to J22 Remote control terminal and simply snip one end of each. If you are not sure then be noted the diodes D33, D34 are on the top of the IC8 chip which is on the top of the backup battery cell.(On the right side from this battery is big IC9 microprocessor) Very simple, but it's amazing just how many screws need removing in the process!

IC-735 Schematic

IC-735 Gen TX mod

IC-735 Gen TX mod

IC-735 Service manual

IC-735 files

73 - Petr, OK1RP

60m - Tropical band in USA

60 Meters: Five Specific Channels by ARRL

The FCC has granted hams secondary access on USB only to five discrete 2.8-kHz-wide channels. Amateurs can not cause inference to and must accept interference from the Primary Government users. The NTIA says that hams planning to operate on 60 meters "must assure that their signal is transmitted on the channel center frequency." This means that amateurs should set their carrier frequency 1.5 kHz lower than the channel center frequency.

General, Advanced and Amateur Extra classes:

Channel Center / Amateur Tuning Frequency
5332 kHz / 5330.5 kHz
5348 kHz / 5346.5 kHz
5368 kHz / 5366.5 kHz
5373 kHz / 5371.5 kHz
5405 kHz (common US/UK) / 5403.5 kHz

Amateurs may use USB *only* with a maximum effective radiated power (ERP) of 50 W. Radiated power must not exceed the equivalent of 50 W PEP transmitter output power into an antenna with a gain of 0 dBd.

For details, see the 60 Meter FAQ page.

Tips on working 60m by Scott, NA4IT

Tips On Working 60 Meters

James "Scott" Duckworth (NA4IT) on April 7, 2004

I have been amazed at the conditions on 60 meters, the "channelized" band opened up to amateurs in the US by the FCC. The conditions on this band can go from "local" of a couple of hundred miles to across the US. And at times, you can hear it all at the same time!

Here's a few tips I have found that help when working this band:

(1) Make sure you are on the proper freqs. Your VFO should read the following: 5.330.5, 5.346.5, 5.366.5, 5.371.5, or 5.403.5. These freqs are all UPPER SIDEBAND! It is best if you put them in memory, and leave the VFO locked.

(2) There is no room for "enhanced audio". Your signal needs to be just a normal signal.

(3) Effective Radiated Power (ERP) must be NO MORE THAN 50 Watts! A simple dipole is the best answer with 50 watts at the rig. Mine is up at the apex at 40 ft and slopes down each leg to about 20 ft.

(4) Filtering is necessary for reception. DSP works really well, and a good notch, as well as the use of your RX IF shift helps.

(5) Courtesy abounds on this band. Ragchewers will stand by for DX contacts or a state hunter readily, and the same is appreciated.

(6) Here in East TN, the 5.366.5 frequency is useless. We are secondary users on 60 meters, and there is some type of data transmission there almost 24 hours a day.

Final thoughts:

(1) 60 meters is not for everybody.
(2) I believe if the current operating practices prevail on 60 meters, we could see the FCC open up more frequencies in the future.
(3) 50 watts is more than adequate for communication on this band. It also helps to keep everyone "even".
(4) Listen to it before you open up your rig. It may not be for you.

73, NA4IT Scott

OK1RP comment:
Well the point 1) is a bit in opposite to my article about OSA technique but we will see what will be the best for efficient DXing on Tropical band.

73 - Petr, OK1RP

Wednesday, January 12, 2011

60m - Tropical band in HA


as I promised last time I am trying to reach the new countries with legal operation on 60m band. One of those is also Hungary which is not far away from OK land. It is possible to find some reports from HA stations in the 60m log but there is no active station on the air. So what happends in Hungary with the Tropical band allocation now? I asked my friend Andras, HA6NN who is very interesting in the propagation study and who is kindly willing to make tests with me cross band to 80m band. There is what I got from him about the permitt for 60m:

"Dear Petr,

HA5WH who is the head of a research department of Budapest Technical University is also interested in our tests.

He has organised a nationwide 5 MHz activity for a group of Hungarian stations some years ago. We got two 5 MHz channels then...

I took part in those daily tests which purpuse has been to investigate NVIS propagation.

Now he is to try to ask for 5 MHz channels from the authorities again. It seems to be exciting due to the completely new government down here...

Dr. Andras Gschwindt, HA5 WH is still cooperating with the Hungaria authorities to get one or two channels around 5 MHz mainly for emergency communication.

We do not know the outcome of his negotiations but we have got 5 and 2.5 MHz channels twice in the preceding years so we are confident.

73 de Andras, HA6NN"

OK, I am in touch with Andras and when some good news will arrive then I will let all of You know. I am keeping fingers crossed...

73 - Petr, OK1RP

60m band DXCC countries by Steve, G4TRA - update 12/1/2011

Prefix Country
1 4U1UN United Nations
2 4X4DK Israel
3 5J0A San Andres Island
4 6Y/K3TRM Jamaica
5 8P9MD Barbados
6 8R1PY Guyana
7 9A5KA Croatia
8 9G5CL Ghana
9 9K2YM Kuwait
10 9Z4AF/9Y4BA Trinidad & Tobago
11 A35RK Tonga
13 AH0V Saipan, Mariana Islands
12 AH2L Guam
14 C21TI Nauru Islands
15 C52T Gambia
16 C6ANM Bahamas
17 CE/K7CA Chile
18 CN8SG Morroco
19 CT1BWU Portugal
20 CT3BD Maderia
21 CX/N3BNA Uruguay
22 DL7UVO Germany
23 EB1BSV Spain
24 EI/G4BZP/P/ All EI Ireland
25 FM5WD Martinique
26 FS/K9EL St Martin
27 G4TRA England
28 GD3YUM Isle of Man
29 GI4VIV Northern Ireland
30 GJ4CBQ Jersey
33 GW0VMZ Wales
34 HH4/W3CMP Haiti
35 HI8HCJ/HI8HH Dominican Republic
37 HK0/N0AT San Andres and Providencia
36 HK4CZE/HK5D Columbia
38 HP1AVS Panama
39 HR2J Honduras
40 IK4WTU Italy
41 IS0VSG Sicilly
42 J20RR/MM Djbouti
43 J37K Grenada
44 J6/K8LEE St Lucia
45 J7N Commonwealth of Dominica
46 JW5E Svalbard
47 K4M Midway
48 KH6EK/KH7C/KH7XS/KH6CB Hawahii
49 KH8Q American Samoa
50 KH9/WA2YUN Wake island
51 KL7HBK/.NL7UZ Alaska
52 KP2/K3MD and KP2/K3TEJ St Croix on 18-02-10. US Virgin Isles
53 KP4BI Peuto Richo
54 LA1V LA6Q Norway
55 LZ2DF Bulgaria
31 MM1RAH Scotland
32 MU0FAL Gurnsey
56 N8S Swains Island
57 OC1I Peru
58 OH2AM, OH2R/V/Z, OH2TA Finland
Czech Republic
60 OM8T Slovak republic
61 ON3TD Belgium
62 OX3XR Greenland
63 OY4M Faroes Islands
64 OZ3PZ Denmark
65 PE1ARD Netherlands
67 PJ7/PY1WAZ St Marten
66 PT7AT Brazil
68 PW2M Moela Island
69 PZ5YV Surinam
70 SL4ZXX Sweden
71 SP7LFT Poland
72 SV1ENX Greece (Athens)
73 T30KI West Kiribati
74 T77C San Marino
75 TA4ED Turkey
76 TF3ARI/TF8SM Iceland
77 TG9NX Guatemala
78 TI8AA - TI5N (CQWW) Costa Rica
79 TI9KK Cocos Islands
80 US3QQ Ukraine
81 V26RM Antigua
82 V31ZL/CL Belize
83 V44NE V4/W5JON St Kitts & Nevis
84 VO1MRC Canada
87 VP2ERV Anguilla - Leeward Is
86 VP2MRF Monseratt
88 VP5/W0GJ - VP5T (CQWW) Turks & Caicos island
89 VP9GE/K4AVC Bermuda
90 VQ9LA Chagos Islands
91 W, N, & K USA
92 XE1KK Mexico
93 YJ0CCC Vanuatu
94 YN2N Nicaragua
95 YO2LDC/3BL Rumania
96 YS1CF El Salvador
97 YT6A, YT6B Now 40 Montenegro
98 YU6/YU1EA Yugoslavia
99 YV5ABH Venezuala
100 Z32AF Macedonia
101 ZB2X/ZB2FK Gibralter
102 ZC4CW Cyprus
103 ZD8I Ascension Island
104 ZF2UL/ZF1A / ZF2PI Cayman Islands
105 ZK2V Niue
106 ZK4EAM New Zealand
Note that Canada no longer has legal access to the band and that many countries listed here have been a "once only" look at the band appearing for minutes in a non legal manner, especially in the case of Eastern Europe. The call signs shown may be the only station ever activating the band in some cases, others are just ones I have heard or worked. In other cases there maybe many stations active. For instance ZK4EAM has been the only New Zealand station ever to come on the band, but W,K and N all US station have access to the band. Also there are limits to some countries access, for instance in Finland it is only OH Club station that have access.

Many thanks to Steve, G4TRA for his help and support !

73 - Petr, OK1RP