Tuesday, April 22, 2008

FT-2000 FSK connection

Last week, I connected the FT-2000 with my homebrew interface, which use the opto coupler 4N32, for RTTY FSK keying. Calling CQ for quite some time without any reply and finally find out thatI wasn't getting any shift.

I've used this interface on other radios over the years with no problem, including FT-920, IC756pro and FT-990. Finally I solved the problem, by the help / information from one of the member in the FT-2000 newsgroup .

The 4N32 opto coupler has a 0.50 volt plus collector "on" voltage which is OK under the usual TTL "low" state and has keyed all my other radios with no problem.

The FT-2000 requires the low or "ON" state to be less than 0.4 volts in order to key the FSK line.

I replaced the 4N32 by a 4N37, which has 0.3 saturated voltage (VCE sat) and it works perfect now.

I believe the FT-2000 is the first of the Yaesu radios that makes extensive use of 3.3 volt (low power) CMOS logic. The "low" requirements of the low power CMOS devices is considerably less than the old CMOS and TTL (most of which worked below about .65 volts). The standard for low power CMOS is down around .3 volts

Wednesday, April 16, 2008

C52C - The Gambia 2007 DXpedition

I am one of the lucky station in Hong Kong worked C52C on 40M in the Gambia 2007 DXpedition operated by the OM0C contest team. On 24 Oct 2007, by chance I can stay a little bit longer at home early in the morning, normally I need to leave home at 2200z. I made the contact with several calls, two many competitors (JAs).

Today I received the nice QSL card.

Wednesday, April 2, 2008

CQ World Wide WPX Contest - 2008

Over the weekend, participate in the CQ World Wide WPX Contest, 15M High Power category. The propagation on the first day was terrible, no signal heard from EU, but JAs are workable. The score on the first day was very low and only achieved approx. 300,000

In the morning of second day , the situation was almost the same, and could only work JA, YB, BY, UA9 and with several station from Pacific.

In the afternoon, start from 0700z, EU signal going up and maintained good condition until 11:00z. I am very lucky to catch this opening and boot up my score just over my last year record. Final at 865,686

The equipment used during the contest are:

Yaesu FT-2000

Create 318jr

Heathkit SB-220

Tuesday, April 1, 2008

2006 UK RTTY Contest Award

The award finally arrived on today. I need to wait more than two years for this nice colourful award issue by GM4FDM.