Markus, DC1MTS, shares his portable radio experiences with the CHA-TDL antenna.

My name is Markus and before I discovered amateur radio, I spent most of my free time hiking and cycling. Then I got an Class E license in 2021 and since the middle of 2023 I am QRV under the callsign DC1MTS.

From the search for the perfect antenna solution to the CHA-TDL Deltaloop: My portable adventure

Since I've been allowed to use the radio, I've been looking for ways to combine these two hobbies. As a transceiver I use a Xiegu G90 with a maximum output power of 20 watts and a built-in tuner, which is essential for the antenna I'm talking about here. I have hardly used the microphone, because I have focused on telegraphy since the beginning. This is a real challenge that I enjoy very much.

In the meantime, I can look back on a few experiences in portable operation. With the transceiver, the paddle, a battery, about 10 m RG58, an EFHW antenna and some accessories in my backpack, I often went in search of suitable places for radio operation. Today I know a few suitable places for radio in the area, but they are rare. The pain point is the antenna. In terms of performance, the EFHW may be a good choice. But you first have to be able to hang it somewhere. And that's where it fails more often than I would like. And if I do find a suitable place, it takes a long time until the antenna is finally hanging at a good height. If I'm unlucky, the line gets tangled in a branch, which I catapult into the tree with a slingshot so that I can then raise the antenna by myself.

The antenna installation is a challenge that I don't enjoy at all. And taking my equipment with me "just in case" on a hike in unknown surroundings is rather out of the question for me under these circumstances. So I've been looking for an interesting alternative for a long time. Now I have the opportunity to try out a completely different antenna: the CHA-TDL. A deltaloop as a portable antenna. I was able to test it a few times during a holiday in Brandenburg. But, everyday life has got me back and after work I set off with my backpack to a nearby lake. Right on the shore I find a bench for myself and a path of grass to install the antenna which is quickly set up. A little later, the transceiver, paddle and battery are connected. 10 minutes after arrival I am QRV.

The NVIS technique in amateur radio: communication at medium distances and the experiences with it

The antenna follows the NVIS concept. This is the first time I have heard of it in connection with this kind of antenna and I was a little sceptical at first. Antennas of this type are not designed for long-distance connections. But what does that mean? Purely German connections? Now I know: Even though the antenna may not be a specific DX antenna, my calls are heard - and answered - in various European countries.

NVIS (Near Vertical Incidence Skywave) is used for medium range communication within a regional area. This is achieved by targeting RF signals at a steep angle to the Earth's surface so that the signals are reflected in the ionosphere and return within a limited geographical area. NVIS is particularly useful in situations where conventional long-range HF communications are not possible or inefficient, such as emergency situations or communications between amateur radio operators in remote areas. NVIS technology requires special antennas and frequency ranges and has proven to be a valuable tool for amateur radio in regions with difficult topographical or atmospheric environments.

Installed antenna
Summary: The antenna for uncomplicated portable operation

Today I spotted myself on a POTA activation, making a total of 8 QSO's this evening on the 20m, 30m, 40m and 80m bands. I don't change anything on the antenna when I change bands, I just engage the tuner. 8 QSOs in 3 hours is actually not much and it's a pity that I will miss 2 contacts for a successful activation for DA-0124 in the end. But the number of connections depends also on one's own skills and that's where I'm still lacking. 8 QSO's are actually a good yield for my conditions. I can also remember many evenings at the club station when I went home without making a single entry in the logbook. The results of the Reverse Beacon Network are perhaps more interesting for the evaluation of the antenna.

So there is definitely a lot potential there. And in fact I have only discovered one shortcoming with this antenna so far: The wire between the telescopic antennas does provide a surface for the wind to attack, so that the latter bends considerably more in strong winds than when the telescopic antennas stand alone. Overall, however, my personal conclusion is more than positive. This antenna offers me the possibility of very uncomplicated portable operation. It is easy to transport, quick to set up and I also get my money's worth in operation. And for all those who prefer columns of numbers to colourful pictures, here is an excerpt from the raw data of the RBN project for the day in question. The transceiver was set to 16 watts output power.

At 20m:

SP SP8R 8 16:52:51
HA HG8A 12 16:53:52
TF TF3Y 14 16:53:53
UA9 RU9CZD 10 16:53:57
SV SV8RV 6 16:53:58
LZ LZ5DI 6 16:54:00
LZ LZ4AE 6 16:54:00
OE OE9GHV 10 16:54:07
HB HB9DCO 11 16:59:36
HA HA6PX 10 17:00:23
SM SE5E 9 17:36:17
EA EA5WU 7 17:36:18
DL DC8YZ 37 17:36:50
HA HA6PX 16 17:36:55
DL DC8YZ 27 17:48:20
OE OE9GHV 22 17:55:05
UA RN4WA 4 17:55:07
HB HB9DCO 19 17:55:08
S5 S53WW 26 18:01:28
S5 S53A 26 18:01:28
S5 S50ARX 12 18:01:30
EA EA5WU 11 18:01:32
HB HB9DCO 22 18:01:33
DL DL0PF 7 18:01:34
DL DL0LA 22 18:01:36
HA HG8A 10 18:03:12
OE OE9GHV 20 18:03:16
I IK4VET 13 18:03:56
I IK4VET 24 18:12:13
OE OE9GHV 20 18:12:16
DL DL0LA 24 18:12:17
S5 S53WW 23 18:12:17
EA EA5WU 19 18:12:17
S5 S50ARX 27 18:12:18
S5 S53A 29 18:12:19
HB HB9DCO 20 18:12:21
HA HG8A 14 18:12:21
GM MM0ZBH 12 18:15:29
HB HB9BXE 17 18:15:31
UA RK3TD 9 18:15:31
TF TF3Y 16 18:17:38
UA9 RU9CZD 10 18:18:02
LZ LZ5DI 8 18:21:11
S5 S53A 33 18:22:19
EA EA5WU 24 18:22:20
I IK4VET 16 18:22:22
HB HB9DCO 18 18:22:28
S5 S53WW 23 18:31:54
GM MM0ZBH 11 18:32:58
S5 S53A 33 18:33:00
F F8DGY 15 18:33:01
LZ LZ4UX 6 18:33:04
S5 S53WW 23 18:33:05
UA RZ3QS 11 18:33:08
TF TF3Y 9 18:33:41
UA9 RU9CZD 9 18:33:42
EA EA5WU 23 18:33:43
I IK4VET 12 18:33:44
UA RN4WA 9 18:35:01
LZ LZ5DI 8 18:35:04
UA RK3TD 10 18:35:04
BY BD8CS 12 18:35:06
EA EA1URA 9 18:35:43
OE OE6TZE 8 18:35:45
LZ LZ7AA 7 18:35:48
GM MM0ZBH 17 18:35:51
UA RK3TD 11 18:36:16

At 30m:

EA EA2CW 17 17:06:14
OH OH6BG 20 17:06:14
SM SE5E 10 17:06:17
DL DL8TG 5 17:06:21
ES ES2RR 18 17:07:57
OK OK4QRO 18 17:08:01
I IK4VET 17 17:24:41
S5 S53A 6 17:24:43
ES ES2RR 17 17:24:43
OH OH6BG 25 17:24:45
OE OE6TZE 13 17:24:45
SM SE5E 15 17:24:46
S5 S53WW 22 17:24:47
DL DL8TG 7 17:25:21
I IK4VET 16 17:25:22
EA EA2CW 17 17:25:23
HB HB9BXE 14 17:25:24
HA HA1VHF 10 17:25:25
EA EA1URA 23 17:25:29
DL DL0PF 13 17:26:02
OK OK4QRO 15 17:26:06
HB HB9DCO 6 17:26:06

At 40m:

SM SM7IUN 13 18:49:36
DL DL0PF 7 18:49:37
PA PE5TT 10 18:49:39
DL DL9GTB 5 18:49:39
OK OK4QRO 16 18:49:44
DL DL8TG 11 18:49:45
DL DM6EE 12 18:49:45
ON ON6ZQ 15 18:50:59
OE OE9GHV 18 18:52:11
OH OH6BG 11 18:52:11
I IK4VET 12 18:52:15
ES ES2RR 17 18:52:18
F F8DGY 17 18:53:38
S5 S53A 18 18:53:41
SM SE5E 12 18:53:41
PA PA8MM 11 18:53:44
OH OH6BG 10 18:58:59
PA PE5TT 12 18:59:07
GM MM0ZBH 14 18:59:21
OE OE9GHV 21 19:04:38
DL DL8TG 14 19:07:44
SM SM7IUN 12 19:07:45
S5 S53A 14 19:07:47
F F8DGY 14 19:07:50
G G4ZFE 4 19:07:51
DL DC8YZ 13 19:07:53
ES ES2RR 14 19:08:04
G G4HSO 12 19:08:16
DL DK9IP-1 9 19:08:23
DL DM6EE 17 19:08:25
OK OK4QRO 16 19:09:10
OH OH6BG 9 19:09:12
ES ES2RR 15 19:11:38
DL DM6EE 16 19:12:29
S5 S53A 15 19:12:42

At 80m:

DL DL1HWS 7 18:40:13
DL DL9GTB 7 18:44:14

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