Heltec ESP32S3 V3 very low Tx power

Hi friends! I just arrived in the community and i will make a base repeater for my city on the top of the hill, using the local ham club’s tower. However i was trying to test my Heltec ESP32 V3 just purchased and i have noticed that the output power when transmitting is much lower than the other device i have (Lilygo T3 S3). I put both with exact same configuration in my Spectrum analyzer, and i got the average output peak around 5.6dBm while the Heltec V3 at around -26.6dBm, which is a crazy difference, taking into consideration that both usd the 1262 LoRa chip. The setup was exactly the same, cables, connectors, all the same. Does anyone have any idea of what may be going on? Thanks!!

i bought 3 and they all suck ( thought was another issue ).
how did you measure output power?
I bought a NanoVNA because the internet says its the antennas… and the antennas are all fine. I even used parts from my FPV gear and made an antenna. still can barley get across the yard. How Can i use the NanoVNA to test the output power ?? ( i was thinking the pigtail wires maybe shorted, i am not wondering if they are just poorly manufactured or went thought a test that messed up the radio)

Edit to my post:
1 of the 3 was bad ( maybe is output-ting 10 mW , it can barley get across the yard)
1~2 of my pig tails for my antennas also eat signal.
I had to make my own pigtail and antennas. and test alot.

Do need a way to test output power. like a standard test or some sort.

There are RF power meters that are cheap, just take a look on Ali.

OK, they might not be precision devices, but you can ‘calibrate’ them against a known good working node. You would need some test software that could send out a packet that was a few seconds long.

The alternative could be a standard test where you look at the RSSI of a packet over a short distance, so 50M, in a standard environment. That could just be a large flat open space with nothing around such as a footbal pitch. The transmitter would need a ‘referance’ antenna, which could be an easy build 1/4 wave vertical with radials. Record and publish the packet RSSI at the 50M. The results on a field in Europe should be the same as on a field in the USA. You can also use this method to compare the real world performance differances between differant antennas, no VNA or SWR meter needed.

Trying to figure out if I have this problem or not.

Done some range testing around my neighborhood and got around 5-6km at best. Seem ok to me on a relatively flat area with some obstructions.
Then I’ve done a longer range tests with a friend, around 20km many times where I can rx just fine but not a single message went through from me. Ive done this multiple time and in slightly different locations.

Ive also done this where the other party has an identilac setup to me. With this its the same story. So naturally I’m thinking maybe I have a bad Heltec chip or not getting full tx power.

…or maybe its just a terrain thing? Can the terrain effect the signal that it goes the other way just fine but not the other?