什么时间、什么波段更有机会通联到这两个大洲呢？

我这儿晚上9点到早上6点前 40米波段有美国台

可用pskreporter, dxview之类的网站实时观察，并用FT8先做快速测试。

晚上7兆打美国，下午的21兆、28兆打欧洲、非洲

FT8也可以，但是非洲没打过，北美可以

@"BH7JUO"#p50042 昨天晚上试了试美西，40米波段。能收到不少台信号，pskreport能看到大量美西电台信号报告。说明信号能出去、能进来。但是无法通联，看FT8解码的消息美西和BY台双方互相都叫不通

@"BG5BJM"#p50504 40米波段天线尺寸大，就算缩短振子，想要效率高也不能缩短太多，并且限制了性能，而且波段底噪比较大，影响通联成功率。相对来说高波段天线尺寸小，噪音比较小，可以使用全尺寸天线，天线效率高通联成功概率更大

@"BH7JUO"#p50635 谢谢。我手里只有20米的全尺寸DP，以及更高波段的拉杆 GP DP。下次再试试

How to connect Africa and North America?

BG5BJM

What time frame and specific trading range offer the best opportunity for cross-continental connectivity between these two continents?

BD6MM

I have US stations in the 40-meter band from 9 PM to 6 AM.

BI4JMS

Um, I'm looking for a QSO with someone in Africa.😇😇

BH7JUO

对于7区：
非洲：下午4点之后到晚上10点，15-10米高波段，270度方向
北美：早上6-9点，15-10米高波段（有时20米也有），30度方向，美西；晚上8-11点，SP 0度方向，20-15米中高波段美东，或LP 180度方向15-10米高波段美东/加勒比（常见FT8或CW）

BG5BJM

BH7JUO Last night, I tested the West Coast station on a 40-meter band. I was able to receive signals from several stations, and PSKReport showed numerous reports of West Coast radio stations. This indicates that the signal can go out and come in. However, I couldn't make contact with either station. According to FT8 decoding messages, both the West Coast and BY stations reported being unable to communicate with each other.

BG5BJM

BH7JUO Around noon today, I was able to make contact with the United States West Coast and the Canary Islands in Ghana. It seems that I used their large Yagi antenna. Although the propagation prediction didn't show any openings, I was still able to make contact on two frequencies, which is quite surprising.

Ken

Use websites like PSKReporter and DXView to monitor in real-time, and then use FT8 for a quick test.

BH4GQD

Evening: 7:00 AM - 8:00 AM, calls to the United States Afternoon: 21:00 - 28:00, calls to Europe and Africa

BH9FPK

When targeting a distant object, isn't it done using GP?

BI6LVP

FT8 is also an option, but it hasn't been used in Africa yet. It can be used in North America.

BH7JUO

BG5BJM 40-meter band antennas are large, and even if you shorten the oscillator, you can't reduce it too much to achieve high efficiency. This also limits performance. Furthermore, the noise floor in this frequency range is relatively high, which affects the success rate of communication. In contrast, high-frequency antennas have smaller sizes and lower noise levels, allowing you to use full-sized antennas, resulting in higher efficiency and a greater probability of successful communication.

BG5BJM

BH7JUO Thank you. I only have a 20-meter full-sized DP cable, as well as a higher frequency GP DP cable. I'll try it next time.

BH9FPK

Full-size inverted V + 50 watts

CQ-BG8LTU

January 17th, 2025 evening - January 18th, early morning: Communication using FT8 on frequencies of 40m, 20m, 17m, and 15m.
I successfully connected to South Africa, but I didn't receive any signals from North America. However, I did see that Japanese channels were consistently communicating with North American channels.
I then checked using pskreporter.info, and I found that my signal could reach North America.

BH7JUO

First and foremost, DX communication must be audible; then you can call. Because generally, the factors that affect successful DX communication are reception, not transmission.

BG5TOX

The person upstairs made a very valid point.

BG2MLK

dmr TG91 group

BH7JUO

BG5BJM FT8 is very stable, and there's a good chance of making contact with stations in the US and Europe between 6 AM and noon. However, it's impossible to accurately determine the time in Africa (specifically Ghana). In my previous competitions, I used a 15-meter antenna pointed at 30 degrees to transmit in the morning, but I was able to receive signals from European stations as well. This is difficult to explain with conventional propagation models. Due to the very active solar activity in recent years, there are many opportunities to make contact on the 15-meter band worldwide, and the probability of making contact is higher than in other frequency bands. Furthermore, it doesn't necessarily follow the patterns I described earlier (which apply when solar activity is moderate or low). DX operators are advised to pay close attention to the 15-meter band.

BG5BJM

BH7JUO Learned it, thank you.👍

BG5BJM

BH7JUO It seems that even the most directional antennas can transmit signals in all directions.😁

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