Tropical band (60m - 5MHz) DX Operation - CW ONLY !!!: 60m band tech

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.

Showing posts with label 60m band tech. Show all posts

Friday, March 1, 2019

DARC: Radar makes 5 MHz band 'useless' !

Germany's DARC reports: Once again we have problems with short wave radars. On almost every evening at 5310-5410 kHz the Russian coastal radar 'Sunflower' broadcasts. This also makes our new miniband useless

A Google translation of their post reads:

The system is located near the city of Makhachkala on the Caspian Sea. Acoustically we perceive it as a deep hum. It transmits in FMOP (Frequency Modulation On Pulse) with 43 sweeps / sec and captures aircraft at a range of up to 450 km.

Over water ships are recognized. Even stealth planes can be classified. The system is so successful that the Chinese operate several "sunflowers" on the east coast. Chinese OTHs (Over-Horizon Radars) work almost daily in the 20-meter band.

In the mornings we can often receive them with high field strengths. They send in blocks of several seconds and jump over wide frequency ranges. Very noticeable is the radar, which resembles a foghorn sound (66.6 sweeps / sec). The worst "QRM brooms", however, are the broadband radars of the Chinese. They work with 10 or 20 sweeps / sec and a signal width of 160 kHz.

In the mornings we find them in the 20 m band and in the evening also in the 40 m band. There they are particularly noticeable when the transmission line is in the dark. At the moment we have extreme problems with the new Container Radar from Russia. It works as an over horizon radar in FMOP with 40 sweeps / sec and a signal width of about 40 kHz often for hours in the 20 m band. In the past few days we see two systems side by side on our SDR screens.

The station is located north of Penza and not far from Saransk. On the S-meter we see S9 + 40 dB and sometimes +50 dB. The DARC-Bandwacht has informed the BNetzA-Konstanz [Federal Network Agency].

Please visit the Bandwacht website again and again and click on the current intruder http://www.iarums-r1.org/iarums/latest.pdf

The newsletters are also recommended. The image material there should also serve for further education.

The website of the Bandwacht and the IARU monitoring system is http://www.iarums-r1.org/

This is reported by Wolf Hadel, DK2OM, from the DARC-Bandwacht.

DARC https://darc.de/

Note: The question is if it is the issue and blocking point for ham radio operation on the 60m band as there is NO ham radio traffic at all for several months. Just PC controlled CB chats...

73 - Petr, OK1RP
.../-.-

Friday, January 19, 2018

The Icom IC-735 on 60m band article revisited...

Hi all,

I decided to revisiting the old article about the 60m band modification of the Icom IC-735. Thanks to Rudi, DK7PE for letting me know about the non-functional link in that article. Also I found major mistake by copycats or even original author of the mod article on internet so I decided to completely reworking it...

https://60mband.blogspot.ch/2011/01/icom-ic-735-on-60m-band.html

73 - Petr, OK1RP
.../-.-

Thursday, January 26, 2017

Putting the K2 on 60m using K60XV module

Putting the K2 on 60m band using K60XV module

The K60XV adds 60-meter ham-band coverage to the K2 and K2/100 transceivers. In addition, it provides a low-level (0 dBm) split path interface for use with transverters such as the Elecraft XV Series.

60 Meters
Revision 2.04 K2 firmware allows the operator to quickly hop among the five fixed channels, as well as do channel-based scanning. The KPA100 option can be also used on 60 meters, but units shipped prior to March, 2004 will require modification (see page 2 of assembly manual).

Complete manual is here.

Specifications

60-meter coverage Approx. 5.0 to 5.5 MHz; see text for permitted transmit frequencies

Transverter T/R control PIN diode switching

Transverter output Low-level, approx. 0.1-1.0 mW (-10 to 0 dBm); linearized RF/ALC detector

Current drain Typically 1 to 2 mA in receive mode, 2 to 15 mA transmit

PCB size 2.0 x 2.6" (5.1 x 6.6 cm)

Firmware Requirements

K2: Revision 2.04P or later main microcontroller firmware is required (U6, Control board), and revision 1.09 or later I/O Controller firmware (U1, RF board). Serial number 4060 and higher K2s already have these revisions. To check the revision, hold any switch while turning the K2 on. Two numbers will be displayed: your main microcontroller revision on the left (e.g. 2 . 0 3 D ), and the IOC revision (e.g. 1 . 0 7 ).

If either is not current, you must obtain an update from Elecraft (order #FWK2MCIO). This new firmware is included free of charge with the purchase of the K60XV kit on request.

Source: http://www.elecraft.com

73 - Petr, OK1RP
.../-.-

Kenwood TS-590 (ver.E) TX modification for 5MHz by Roar, LA4AMA

Kenwood TS-590 TX modification

The E version (Europe) has no TX on 5 MHz, but the K version (USA has 5 MHz TX between 5.250 MHz and 5.450 MHz. According to the service manual (page 120) the difference between E and K version is a jumper (R968) which is installed in E version but missing in the K version.

There are 2 possible TX extensions on the E version, either full TX (1.705 – 30 MHz) or just open up 5 MHz (cut the R968 jumper and make it into a K version).

Complete modification guide is here

Thanks to Roar, LA4AMA for sharing this mod.

73 - Petr, OK1RP
.../-.-

Sunday, January 16, 2011

Experimental 60m Inv Z dipole for pocket size lots

Hello,

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

Thursday, January 13, 2011

60m - Tropical band antennas

Hello,

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.

http://www.digitalham.co.uk/antenna/60m_antennas.php

73 - Petr, OK1RP

Icom IC-735 on 60m band

Hi,

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!