Curious if they have a detector built in. Guessing with the SMA, it's AC made to drive 50 ohms. Will wait for your report.
Yea just RF out @ -50dB
Refer to pic for the testing setup I used to check the measurements using a higher power input from my little test transmitter (Baofeng UV-5R).
The actual measured output powers of the UV-5R checked with a hp 436B (no coupler inserted):
VHF low/high Watts: 1.8, 5.1
UHF low/high Watts: 1.4, 4.0Some years ago I made an SWR test load for calibrating the SWR / power meters on HF transceivers - meaning up to 29 MHz. It uses three 50 ohm RF load resistors and, using a switch, can present SWR 2 or 3 to the transmitter. I used this to check the SWR on 146 and 445 MHz. Given the fact I never designed it for use with VHF and UHF bands it still gave me results that tell me the coupler will work in the application I'm working towards. I need to design a better SWR test load for these higher bands (better shielding and layout for higher frequencies).
Using this SWR test load, I measured the FWD & REV port powers under load conditions that should cause a VSWR of 2 and 3 and so the coupler outputs (FWD & REV) should give us (or a microcontroller) the power levels to calculate it.
Corrected port power used below in dBm (actual port power -50 dB less)
VSWR 2VHF 146.0 MHz
F 36.4, R 28.4, calculated VSWR 2.4
UHF 445.0 MHz
F 36.7, R 26.8, calculated VSWR 1.9
VSWR 3VHF 146.0 MHz
F 35.6, R 30.0, calculated VSWR 3.2
UHF 445.0 MHz
F 35.0, R 29.0, calculated VSWR 3.0
In addition to the wideband plot of coupled FWD power output provided in earlier post, I took precise measurements of the advertised -50 dB coupling for each of four ham bands, for use in the software to come later:
6m band (52 MHz): -50.8
2m band ( 146 MHz): -50.8
1.25m band (222 MHz): -51.2
70cm band (445 MHz): -50.4
At this point I'm pretty satisfied that the Putnam dual directional coupler will be satisfactory for this project, so I'll move forward and start collecting some parts I'll need to check it out with a microcontroller.