环境概述：京南，5层窗口向北，无防盗网无室外阳台，斜对面特殊单位无法架设端馈，斜坡屋顶无法到楼顶考虑还有相机无人机露营装备等，无法承担野架重量，A证暂不考虑上B搞短波于是就发现2米波段的VHF也可能实现超视距通联，准备跳个坑试试目前V段可用设备： 500DR 配 CAT283 ，天线 SG7900 & A144S5R2 天线可以考虑加一根NR22LH 电台可以考虑IC9700 配 CAT273 问题： 1、2米VHF频段活跃度如何？通联距离怎样？方向性明显么？ 2、2米VHF搞远距离，FM模式够用么？是否有必要IC9700搞SSB或CW？

144MHz DX 这个坑太深了，建议先去短波区域先练级再回来…… 技术高、传播少、人数少，这三个综合在一起就意味着难度很大通常来说更多的会出现在4-7月份之间，其他季节偏少可以选择APRS或者144.460FT8频率蹲守 [upl-image-preview url=https://storage.hamcq.cn/2024-10-16/1729055948-936826-gdzwcaiamae-5r5.jpg]

专门上机器2M DX就算了，传播很少开通吧

考B才是救赎之路，2米DX就是退坑之路。

@"Liridice"#p37025 救赎之道就在其中

看你怎么理解DX，多远算DX。周边500公里以内还是更远。个人理解： 1、VHF DX机会少，成功通联难度系数高。 2、天线要好，有条件就搞多单元的八木，最低也得搞个几米长的玻璃钢天线。 3、大于500公里推荐SSB、FT8。

https://vhf.dxview.org/ https://www.pskreporter.info/pskmap.html 还可以结合aprs看传播

@"BI4PMQ"#p37024 属实有点劝退了

@"Liridice"#p37025 12月才够资格考B，问题是没地儿架天线，VHF天线不是还小点么…

@"BD6OC"#p37045 按5层楼高度和遮挡情况，能通到100公里外，呼号不是1区的就算。多单元八木没地方架，最多就是个2.5m的苗子。如果没被劝退，9700得买，get✅

@"troilus"#p37048 感谢，回去研究下🤣

难，在城市里考虑遮挡和底噪的话VHF传播不太好，没高度或者八木最远也就100公里，而且传播还很少开通

Questions about 2-meter VHF DX?

BI1TSS

Environmental Overview:
Beijing South, 5-story building with windows facing north, no security mesh or outdoor balcony, cannot install rooftop antennas due to the presence of a special unit directly across the street, and the roof slope does not extend to the top floor.
Considering factors such as cameras, drones, and camping equipment, which would add to the weight, I am not currently considering upgrading from an A license to a B license for shortwave radio.
As a result, I discovered that VHF in the 2-meter band could also achieve long-range communication, so I decided to try it out.

Currently available V-segment devices:
500DR with CAT283, antenna SG7900 & A144S5R2
The antenna could also be upgraded with an NR22LH.
The radio could consider using the IC9700 with the CAT273.

Question:
1. What is the activity level in the 1-2 meter VHF frequency band? What is the communication range? Is there a significant directional characteristic?
2. Is a 2-meter VHF suitable for long-distance communication? Is FM sufficient, or is an IC9700 necessary for SSB or CW operation?

BI4PMQ

Let's just focus on using the 2M frequency for operating from a station; it seems like opening up propagation would be difficult.

BI1TSS

BI4PMQ It's definitely off-putting.

Liridice

Passing the B exam is the path to redemption, while 2-meter DXing is the path to retirement.

BI4PMQ

Liridice The path to redemption lies within it.

BI1TSS

Liridice I won't be eligible to take the B exam until December, but I don't have a place to set up my antenna. Also, aren't VHF antennas supposed to be smaller?

BD6OC

Let me know how you understand DX (distance), and what distance you consider to be DX.
Within 500 kilometers or further.

My personal understanding:
1. VHF DX opportunities are rare, and the difficulty of establishing successful communication is high.
2. The antenna needs to be in good condition; if possible, install a multi-element Yagi antenna. At the very least, you should have several meters of glass fiber antenna.
3. For distances greater than 500 km, SSB and FT8 are recommended.

BI1TSS

BD6OC Based on a height of 5 floors and the degree of obstruction, it can reach 100 kilometers away; if the callsign is not in Zone 1, then it's considered effective. A multi-unit Yagi antenna doesn't have enough space to mount, so the maximum size would be around 2.5 meters. If you don't get discouraged, buy the 9700.

troilus

https://vhf.dxview.org/ https://www.pskreporter.info/pskmap.html

It can also be combined with APRS for tracking propagation.

BI1TSS

troilus Thank you, I will look into it further.🤣

BI4PMQ

BI1TSS If it doesn't work, add some emotion, or use a different approach.

Liridice

BI1TSS You could try a 6-meter antenna, but 6 meters is best during the summer months. It's currently past that season, and it can also be difficult to use indoors.

BI1TMQ-AK6MZ

It's difficult to achieve good propagation in VHF frequencies within a city, especially when considering obstructions and ground noise. With a low height or a Yagi antenna, the maximum range is typically around 100 kilometers, and the signal strength is also quite weak.

BI1TSS

BI1TMQ-AK6MZ 弃坑弃坑，等满6个月考B折腾短波

BI1TSS

BI4PMQ 加感OK，野架OK，消停俩月考完再折腾

BI1AVH

Instead of a fixed rack.😔

BI1TSS

BI1AVH 收到，还是得出去

BI1TSS

Liridice Hmm, all machines that are 6 meters long must be used with shortwave radio, and you also need to pass the B exam in June to obtain a license.

BG2KAJ

You can start with APRS first, and then consider 2m FT8 when you're ready.
There are still many people using APRS and FT8 on 2 meters in Beijing. The most active region for 2-meter FT8 is District 4, and I also operate a 2-meter FT8 station in District 2 during the propagation season.

BI1TSS

BG2KAJ I received APRS from a distance of 300 km, and I was the first to connect my D-Star repeater with KVT teacher via reflector.

BG2KAJ

It is possible to use a vertical antenna for 2m FT8 to Japan (JA) in the summer, and there are precedents for this. However, using an eight-element Yagi antenna is preferable, and it is also possible to achieve BY-JA DX with a three or five-element Yagi antenna within the city.

BD4RHV

Typically, a 2-meter (14.2 MHz) window is best during May-August. Using an FT8 radio with a 770H transceiver, I was able to make contacts on the JA, BV, and Russian Far East bands for the first time this year. The typical contact duration is one or two hours, and point-to-point communication is very clear. However, the signal strength can vary significantly depending on distance, making it quite unpredictable.

BI1TSS

BD4RHV Received. Based on this, whether you can achieve 2 meters depends on factors like weather and location, as well as luck. Since you're just starting out, the difficulty might be a bit too high. Perhaps waiting until mid-June when shortwave activity picks up would be better.

Liridice

BI1TSS 比如X6100和IC-705都是有50MHz波段核准的，可以上A照。

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