T1 Preliminary Tests

I have now done som basic tests of the T1. I decided to tune the MP-1 to somewhere in the 40 meter band and then try to match it with the T1 on the other bands. The initial setting of the MP1 was as follows:

     7000 kHz     0 bar
7015 kHz 0 bar
7030 kHz 1 bar
7040 kHz 2 bars
7055 kHz 3 bars
7080 kHz 4 bars
7110 kHz 5 bars
7150 kHz 6 bars

Bars in this context is the number of bars on the FT-817 SWR meter. Around 6-7 bars the HIGH-SWR flag is trigged in the FT-817.

Now, after inserting the T1 in between the FT-817 and MP-1 the SWR went down to 0 bars across the whole range mentioned above. It is thus very true that the T1 can easily extend the range of very narrow band antennas.

At this point I should mention that the very first tuning took very long time, something like 20 seconds and didn’t reach a very good match. This was bothering me, since the antenna was already tuned to 40 meters and according to the manual, the T1 should be able to match within few seconds. I then noticed that the soldering of the antenna plug wasn’t good enough, so the T1 was actually matching an empty antenna plug on 40 meters! Not bad…

Once I fixed the soldering, I could try to tune on the other bands as well. The results follow here. The actual SWR reading is based on the T1 LEDs:

     80 m     no good match
40 m 0 bars 1:1
30 m 3 bars 2:1
20 m 0 bars 1:1
17 m 5 bars 2:1
15 m 0 bars 1:1
12 m 0 bars 1:1
10 m 0 bars 1:1
6 m 0 bars 1.5:1

Tuning was rather easy: Press and hold the PWR/TUNE button until the green LED is ON then start transmitting within 3 seconds. Toggling between TUNE and BYPASS mode is very easy as well: Tap PWR/TUNE, when the yellow LED flashes tap the BYP/INFO button. Now, either the green or the yellow LED will turn on for a while meaning the the tuner is either in TUNE mode (green) or in BYPASS mode (yellow). You can keep on toggling with the BYP/INFO button as long as one of the LEDs is turned on.

So, it seems that my T1 works. More tests, including the FT-817 remote cable, to follow soon.

Author: Alexandru Csete

Embedded software engineer in the satcom industry during the day. Radio amateur and SDR hacker during the night.