### 背景临近入冬，北方气温下降，可能无法长时间户外架设，由于对天线了解有限，目前手里有的GP、便携正V、20米端馈，想最近学习制作便携效率较高的QRP电台天线，CW 5W,SSB 10W,设备IC-705,应对日常背包野架，不额外带其他灯架之类，架设地点一般也在市内公园或者郊区 ### 期望效果普通14寸电脑包能装的下电台、天线、电源、馈线，不借助天调，不外带支撑杆等大型设备 ### 已尝试方案今年夏天尝试过长线方案： **尝试方案1 端馈形 Random Wires** 1平方特氟龙镀银线，22米+ICOM AT130&ATU100DIY天调，AT130大家都不陌生，接线就能调到底的SWR，但是对于QRP通联效率不高，而且太过笨重体积庞大且需要单独供电，ATU100表现更差，同等环境下在保证良好接地的情况下只能当收音机，当时架设条件是振子离地3米结论：失败 **尝试方案2 垂直接地GP Verticals** 便携GP和便携正V都有，GP缺点就是需要良好的地网支撑，而且单波段，需要频繁调整拉杆，波段切换方面较为繁琐，便携正V需要外带灯架，不适合单人无载具作战结论：备选 **待测方案** 4:1 Random Wire 9:1 Random Wire 最近也在研究国外QRPer在使用天线，使用较为多且足够轻便的还是端馈类天线，希望有QRP经验的老师们留言交流。

@"BI1RRE"#p83232 gp地网可以尝试屏蔽布，比一般的线地网铺设要快速和便捷，想要效果更好的话可以尝试双地网叠加，原文本社区的链接在这里：https://forum.hamcq.cn/d/3584

QRP 就尽量选择偶极类天线了找两棵树拉水平DP 那是最好的了

@"BH3XZT"#p83235 GP暂定，因为GP是最早入手的天线，不论是m哥的车载gp还是JYR的中部加感GP都有试过，目前备选，因为GP需要带地插+gp底座+拉杆+地网体积上不占优势，如果乘坐地铁会因为地插是一跟长钉子有时候会比较麻烦。

@"BA7NNC-JOE"#p83236 DP也在考虑，没什么把握每次都能找到合适距离的树木来架设

要小体积可以20米端馈，用49：1的unun，唯一的缺点是发射仰角高，要想降低仰角得找7米以上的树拉正v

GP Only，部署不算麻烦，但对高度没要求就可以实现低仰角

我的方案是垂直端馈。一根12米长的玻璃钢杆+地锚，10.2米长阵子附在玻璃钢杆上，端馈匹配盒。 40米段就是1/4波长的GP，20米段是半波端馈，17米段接近5/8端馈，15米段是3/4端馈，基本都在谐振状态，20/17/15米段都不需要太正式的地网。携带架设都简单，仰角低适合DX。

不带支撑杆肯定只有GP了，考虑下相控阵？

@"BI1KPO"#p83251 端馈能立起来或者用撑杆拉倒v都能有效拉低仰角，我之前横着水平架最多只能出省😭顺便问问有没有便携撑杆推荐，现在每次都是用矿泉水瓶往树上扔的，怕哪次卡树上就完了

Discussion on high-efficiency QRP radio antennas for elevated ground radials

BI1RRE

Background

As winter approaches, the temperatures in the north are dropping, making it difficult to set up antennas outdoors for extended periods. Due to limited knowledge of antennas, I currently have a GP, portable vertical antenna, and a 20-meter feedline. I am interested in learning how to build a portable QRP radio antenna that is highly efficient, suitable for CW (5W) and SSB (10W) operation. The equipment includes an IC-705 transceiver, intended for everyday backpacking and field use without requiring additional support structures like tripods. Typical installation locations are within city parks or in the suburbs.

Expected outcome

A standard 14-inch computer bag can accommodate radios, antennas, power supplies, and cables, without the need for external tuning devices or large support poles.

Tried solutions

I tried a long-term plan this summer:
Option 1: End-fed random wires
1 square meter of silver-plated Teflon wire, 22 meters + ICOM AT130&The ATU100DIY antenna tuner is a popular choice, and the AT130 is also well-known. It allows you to adjust the SWR simply by connecting wires, but it's not very efficient for QRP communication, and it's also bulky and requires separate power. The ATU100 performs even worse under similar conditions, and in a situation where good grounding is ensured, it can only be used as a receiver. At the time of installation, the coil was 3 meters above ground.
Conclusion: Failure
Option 2: Direct GP Verticals
Both the portable GP and portable V are available. However, the disadvantage of the portable GP is that it requires good ground support, and it uses a single frequency band, which means frequent adjustments to the steering handle and complex switching between frequency bands. The portable V also requires an external tripod and is not suitable for solo operations without a vehicle.
Conclusion: Alternative
Test plan
4:1 Random Wire
9:1 Random Wire

I am also currently researching the use of antennas in QRP, and I'm particularly interested in using lightweight, multi-band antennas, specifically those with direct feed. I would appreciate any advice or experience from experienced QRP operators who can share their knowledge.

BH3XZT

BI1RRE A GP ground network can attempt to block interference, which is faster and more convenient than laying a typical cable-based network. For better results, you can try layering two ground networks. The link to the original community content is here:https://forum.hamcq.cn/d/3584

BI1RRE

BH3XZT The GP is currently the preferred option, as it was the first antenna I acquired. I've tested both the m哥 car-mounted GP and the JYR central/extended GP, and the GP remains a viable choice. However, the GP requires an extension cable + base + pull rod + ground wire, which makes it less convenient in terms of size. Also, using it on the subway can be problematic because the extension cable is a long spike that might get caught sometimes.

BA7NNC-JOE

QRP: Whenever possible, choose dipole-type antennas.

Find two trees, perform a horizontal DP (dynamic programming) on them; that's the best approach.

BI1RRE

BA7NNC-JOE
DP is also considering this option, but he's not confident that he can consistently find suitable trees to use for installation.

BD8DIN

For a small size, you can use a 20-meter antenna. Using a 49:1 unun (unit untuned), the only drawback is that the transmit angle is high. To reduce the angle, you need to find a tree that is at least 7 meters tall and position it correctly.

BG5EIB

Electric Screwdriver

BG2KAJ

GP Only, deployment isn't too complicated, but it can achieve low viewing angles even without high accuracy.

BI1KPO

My proposed solution is vertical polarization feed.
One 12-meter long glass fiber pole + ground anchor, with a 10.2-meter antenna attached to the pole, and an end-feed matching box.
The 40-meter section uses a 1/4 wavelength GP, the 20-meter section uses a half-wave feedline, and the 17-meter section is close to a 5/8 wave feedline. The 15-meter section uses a 3/4 wave feedline. They are all in resonance, and the 20/17/15-meter sections do not require a formal ground system. The portable setups are simple and have a low angle of elevation, making them suitable for DX (long-distance) communication.

BD8DIN

BI1KPO Both tilting and using a support to pull it down can effectively reduce the angle of elevation. Previously, I could only get it across the province when laying it horizontally on a level surface.😭By the way, I was wondering if there are any portable tent pegs you could recommend. Currently, I'm using water bottles to throw up on trees, but I'm worried that one day I might not be able to get them back.

BH7HQT

Without a support pole, it's likely just GP. Should we consider phased array?

BI1KPO

BD8DIN Setting a pole horizontally requires high height, and only poles with half-wavelength heights provide good directionality and angle of elevation. If the height is too low, it becomes like a cannon pointing upwards. Finding a sturdy and portable support pole suitable for outdoor use that is also easy to find can be difficult. You might try searching online marketplaces.

BI1RRE

Update progress:
Recent attempted solutions
Using a radio:IC-705
Transmitting power:5W

Using a 2643625002 magnetic ring winding with a 49:1 unun, employing both self-coupling and non-self-coupling winding techniques, the coil length is 20m with a 1 square meter of Teflon.
Tower height7-9 meters above ground
Number of tests:Approximately 10 times
No self-coupling + 1.5µH compensation inductor + common-mode suppression magnetic ring
Band Frequency range SWR AVG Number of QSOs CW SSB FT8

40 meters 7.0-7.100 1.6 1 0 1 /

20 meters 14.0-14.300 1.2 1 0 1 /

15 meters 21.0-21.400 1.1 16 3 1 12

10 meters 28.0-28.400 1.4 0 0 0 /
Compensation inductor + resonant inductor (1.5 uH) + common-mode suppression toroidal transformer I forgot to bring my computer with me when I went out, so I couldn't test FT8. The testing took 2 hours.
Segment Frequency range SWR AVG Number of QSOs CW SSB

40 meters 7.0-7.100 1.7 0 0 0

20 meters 14.0-14.300 1.1 2 1 1

15 meters 21.0-21.400 1.1 1 0 1

10 meters 28.0-28.400 1.1 0 0 0

Initial testing using a 4:1 and 1:1 BN43-7051 dual-hole magnetic loop antenna for single-band feed, due to the fact that the wires were pieced together from various sources, resulting in a total length of approximately 7 meters.
Therefore, it's not entirely accurate.

Band	Frequency range	SWR AVG	Number of QSOs	CW	SSB
15 meters	21.0-21.400	1.5	2	0	2

I would like to express my sincere gratitude to @BD8BTE for their technical guidance.

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