[amsat-bb] AO-85 and AnyTone TERMN-8R, full-duplex - report (long)

Fri Nov 27 04:06:37 UTC 2015

Hi!

After previously trying a couple of Wouxun dual-band HTs with AO-85 in the
past few weeks (KG-UV8D, KG-UV9D) on AO-85, I went back to a radio I
briefly tested before the AMSAT Symposium last month: the AnyTone TERMN-8R
2m/70cm FM HT. I didn't have much time to try it out then, but I gave it a
try this afternoon on a 48-degree AO-85 pass over the west coast. I used
the same settings in it that I did with the Wouxun KG-UV9D I tested last
weekend, so I could have a baseline to compare this radio against. I was
not surprised with the results.

The TERMN-8R was briefly on the market in the US earlier this year. This HT
was marketed as the first HT that was certified for use in 3 different FCC-
regulated services (commercial two-way radio governed by FCC Part 90, along
with GMRS and MURS). Its receiver covers much more than the 2m and 70cm
bands - broadcast AM and FM, shortwave (HF), and the VHF air band. The FCC
revoked the TERMN-8R's certification for use in the GMRS and MURS (license-
free 150 MHz VHF) services, and ordered its importer to stop selling this
radio. Since amateur equipment other than RF amplifiers operating below 144
MHz sold in the US does not require FCC certification for amateur use, this
radio is legal to use in this country on the 2m and 70cm ham bands by
licensed radio amateurs when complying with the technical requirements in
FCC Part 97.

Now that the legalities are out of the way, the simple question. Can the
TERMN-8R work AO-85 full-duplex?

YES.

I worked a pass this (Thursday) afternoon around 2337 UTC. This was a pass
with maximum elevation of 48 degrees, a good pass favoring the US west
coast. Keeping AMSAT's recent recommendations in mind for working this
satellite (low-power stations can get through on higher passes), and my own
testing that appears to put the definition of "higher passes" as when AO-85
is at least 20 degrees above the horizon, I had about 7 minutes of this
pass where I should have been able to get through. Using the same settings
I had used with the KG-UV9D last weekend, I was able to hear the satellite
well with narrow FM. I used wide FM on transmit, and I think that seems to
work well with these HTs that don't have the deviation that the HTs from
the traditional ham manufacturers (Icom, Kenwood, Yaesu) have.

Here are some key settings I used with the TERMN-8R, which are specific to
each VFO:

Uplink VFO:

T-CDC (01): 67.0HZ
STEP (10): 2.5K
W/N (11): 25K
TX (17): ON
SQL (40): 9

Downlink VFO:

STEP (10): 2.5K
W/N (11): 12.5K
TX (17): OFF
SQL (40): 00

As with the KG-UV8D and KG-UV9D, it does not matter which VFO is used for
transmit and receive. The settings I used were with the upper (A) VFO as my
transmit VFO, and the lower (B) VFO as my receive VFO. This is important
for the TX menu setting, where I disabled transmitting from the receive
VFO. I did not program any memory channels for use with AO-85, as the VFOs
work well for this type of operation. I connected an audio splitter to the
speaker jack, and fed the receive audio to an earpiece and my Sony audio
recorder.

I did not try getting through AO-85 until its elevation was up to about
20 degrees. For my first transmissions as the satellite continued climbing
to its maximum elevation of 48 degrees, I was hearing some noise when I
transmitted that covered up the downlink. This did not last long, as I was
able to hear myself while I transmitted for most of my QSOs. This HT's
receiver is pretty good - a little better than the Wouxun KG-UV8D, but not
as good as the Wouxun KG-UV9D. Using the 2.5 kHz tuning steps on both
uplink and downlink helps a lot. More work for the operator, but the lower-
power stations need all the help they can get, and some of that help is
finer tuning for the uplink signals than you can do with the 5 kHz tuning
steps.

I had a separate station set up in my yard to write an RF recording of this
pass. I used my SDRplay SDR receiver, 8-inch Windows 10 tablet with HDSDR,
and the AMSAT-UK VHF crossed dipole on an 8-foot mast and tripod. I made
sure to press Record in HDSDR, so I had an RF recording. I could tell I was
transmitting with a different radio, but my transmit audio was not horrible
from the TERMN-8R. My transmit audio also sounded OK when I listened to the
recording from my Sony audio recorder. With the occasional fades, there
were times I had audio for a portion of the pass on one recording, but not
the other.

I made 5 QSOs on this pass, with all 5 stations in different parts of
California (KG6NUB and KB5WIA in northern California, three in southern
California - K6FW, N6UK, and KB6LTY). I heard K7TRK in Oregon and N7EC
north of Phoenix on as well, but I did not work these two stations. This
was an orderly pass, stations leaving gaps between transmissions, which
really helps for those using lower transmit power levels. Sawson KG6NUB
was using around 2 watts into an Arrow Yagi and getting through for the
first half of the pass I heard.

I have uploaded the MP3 recording I made from the TERMN-8R, the larger RF
recording I made from HDSDR, and some photos plus a screenshot of how the
pass looked from AmsatDroid Free on my mobile phone, to my Dropbox space
at:

http://dropbox.wd9ewk.net/

Look for the folder "20151126-AO85_Fox1A-DM43", and look for the recordings
with file names containing something around 2340 UTC. Photos have file
names with timestamps in local time (7 hours behind UTC), if you want to
take a look at my setup before AO-85 came up from the horizon.

Since I already had the TERMN-8R, it was on my to-do list to try with
AO-85. I'm glad I tried it out, since now I can say there are at least 3
Chinese-made 2m/70cm HTs that can work AO-85 full-duplex. I found that I
could hear myself while transmitting to SO-50 using the TERMN-8R on very
high passes, but in general it is like those Wouxun HTs I previously tried
with AO-85 - don't bother trying to use it full-duplex on SO-50 or
LilacSat-2 (two V/U FM satellites), without having a second radio nearby.
With the TERMN-8R off the market, I wouldn't recommend trying to pick one
up for working AO-85. If you want to try a Chinese-made HT with AO-85 and
work this satellite full-duplex, the KG-UV9D is a better option.

73!

Patrick WD9EWK/VA7EWK
http://www.wd9ewk.net/
Twitter: @WD9EWK