Hi!
Another day, another radio to try on AO-85. I woke up early, and decided to try another HT on a high AO-85 pass starting at 1350 UTC. I wanted to see if it could work the satellite full-duplex. The radio, this morning: the Puxing PX-UV973. After working AO-85 with it this morning, my (low) expectations were met.
The Puxing PX-UV973 has been on the market a couple of years. It is supposed to handle cross-band full-duplex operation. This radio is still in production, and I picked mine up from Amazon for about US$ 78. It is less expensive than the other radios I have tested so far for full-duplex operation on AO-85, and it shows.
First, the simple question. Can the PX-UV973 work AO-85 full-duplex?
Yes, more or less.
The radio comes with a duckie antenna, and a 7.4V/1200mAh battery pack. The battery pack is smaller than the standard packs supplied with the other HTs I have tested so far. It is also a little bit smaller than the other HTs. As with the others, I did not program any memory channels to work AO-85. I used the two VFOs, putting the uplink into the upper (A) VFO, and the downlink into the lower (B) VFO. Uplink and downlink can be done from either VFO.
I used these VFO-specific settings with this radio, similar to what I have been using with the other HTs:
Uplink VFO:
SQL (005): 9 N/W (014): WIDE T-CDC? (019): 67.0 STEP ? (020): 2.50
Downlink VFO:
SQL (005): 0 N/W (014): NARROW STEP ? (020): 2.50
Another setting I had to enable for full-duplex operation was:
DUPLEX (031): ON
With the smaller tuning steps, I could get the AO-85 downlink lined up easily on my PX-UV973. It was about 5 minutes into the pass before I made my first QSO, with Glenn AA5PK in west Texas. A couple of minutes later, I made another quick QSO with Ed N7EC north of the Phoenix area. The receive audio while I transmitted was not really good - despite the satellite's elevation heading up to 56 degrees at the midpoint of the pass. The HT was able to operate full-duplex, but the other HTs I have tested with AO-85 have done much better. I could still hear myself through AO-85 a couple of minutes after these QSOs, until the trees in a neighbor's yard started to make it tougher to hear. The CW beacon from XW-2F was also starting to overlap with the AO-85 downlink, also.
Using my SDR receive setup (SDRplay receiver, HDSDR on an 8-inch Windows 10 tablet, AMSAT-UK VHF crossed dipole), my transmitted audio sounded OK. Not loud, but it was fine - similar to what I've heard from the other Chinese- made HTs I have tested. I have uploaded the audio recording I made from the HT, the RF recording from the SDR receive setup, and some photos, to my Dropbox space. You can get those files at http://dropbox.wd9ewk.net/ - look for the folder "20151127-AO85_Fox1A_XW2F-DM43". I also heard XW-2F near the end of the AO-85 pass, and I let HDSDR continue writing the RF recording to cover XW-2F until its LOS.
Since the PX-UV973 has been on the market for a couple of years, I did not have high expectations for it working AO-85 full-duplex. I was not surprised to see that it was a poor performer. If I had to rank this with the other 3 Chinese-made HTs I previously tested, this one would be at the bottom of the list by default:
1. Wouxun KG-UV9D 2. AnyTone TERMN-8R 3. Wouxun KG-UV8D 4. Puxing PX-UV973
Don't be drawn in by the low price of the PX-UV973. If you already have it, it can be used as one radio of a two-radio setup, probably as the uplink radio. Or use it for terrestrial repeaters, where it would probably serve that purpose adequately. I now understand why one dealer was hesitant to offer an opinion about this radio's performance for FM satellite work, when I asked about it early last year.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK
Thanks for that information.
I am looking into the woxun radios, and see the kv9d at the top of your rank.
Is this an adequate radio for full duplex satellite operation, how far does it fall behind the American radios?
73 Skyler kd0whb
On Nov 27, 2015, at 12:23 PM, Patrick STODDARD (WD9EWK/VA7EWK) amsat-bb@wd9ewk.net wrote:
Hi!
Another day, another radio to try on AO-85. I woke up early, and decided to try another HT on a high AO-85 pass starting at 1350 UTC. I wanted to see if it could work the satellite full-duplex. The radio, this morning: the Puxing PX-UV973. After working AO-85 with it this morning, my (low) expectations were met.
The Puxing PX-UV973 has been on the market a couple of years. It is supposed to handle cross-band full-duplex operation. This radio is still in production, and I picked mine up from Amazon for about US$ 78. It is less expensive than the other radios I have tested so far for full-duplex operation on AO-85, and it shows.
First, the simple question. Can the PX-UV973 work AO-85 full-duplex?
Yes, more or less.
The radio comes with a duckie antenna, and a 7.4V/1200mAh battery pack. The battery pack is smaller than the standard packs supplied with the other HTs I have tested so far. It is also a little bit smaller than the other HTs. As with the others, I did not program any memory channels to work AO-85. I used the two VFOs, putting the uplink into the upper (A) VFO, and the downlink into the lower (B) VFO. Uplink and downlink can be done from either VFO.
I used these VFO-specific settings with this radio, similar to what I have been using with the other HTs:
Uplink VFO:
SQL (005): 9 N/W (014): WIDE T-CDC? (019): 67.0 STEP ? (020): 2.50
Downlink VFO:
SQL (005): 0 N/W (014): NARROW STEP ? (020): 2.50
Another setting I had to enable for full-duplex operation was:
DUPLEX (031): ON
With the smaller tuning steps, I could get the AO-85 downlink lined up easily on my PX-UV973. It was about 5 minutes into the pass before I made my first QSO, with Glenn AA5PK in west Texas. A couple of minutes later, I made another quick QSO with Ed N7EC north of the Phoenix area. The receive audio while I transmitted was not really good - despite the satellite's elevation heading up to 56 degrees at the midpoint of the pass. The HT was able to operate full-duplex, but the other HTs I have tested with AO-85 have done much better. I could still hear myself through AO-85 a couple of minutes after these QSOs, until the trees in a neighbor's yard started to make it tougher to hear. The CW beacon from XW-2F was also starting to overlap with the AO-85 downlink, also.
Using my SDR receive setup (SDRplay receiver, HDSDR on an 8-inch Windows 10 tablet, AMSAT-UK VHF crossed dipole), my transmitted audio sounded OK. Not loud, but it was fine - similar to what I've heard from the other Chinese- made HTs I have tested. I have uploaded the audio recording I made from the HT, the RF recording from the SDR receive setup, and some photos, to my Dropbox space. You can get those files at http://dropbox.wd9ewk.net/ - look for the folder "20151127-AO85_Fox1A_XW2F-DM43". I also heard XW-2F near the end of the AO-85 pass, and I let HDSDR continue writing the RF recording to cover XW-2F until its LOS.
Since the PX-UV973 has been on the market for a couple of years, I did not have high expectations for it working AO-85 full-duplex. I was not surprised to see that it was a poor performer. If I had to rank this with the other 3 Chinese-made HTs I previously tested, this one would be at the bottom of the list by default:
- Wouxun KG-UV9D
- AnyTone TERMN-8R
- Wouxun KG-UV8D
- Puxing PX-UV973
Don't be drawn in by the low price of the PX-UV973. If you already have it, it can be used as one radio of a two-radio setup, probably as the uplink radio. Or use it for terrestrial repeaters, where it would probably serve that purpose adequately. I now understand why one dealer was hesitant to offer an opinion about this radio's performance for FM satellite work, when I asked about it early last year.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Hi Skyler!
As I have been writing, these Chinese-made HTs can work AO-85 full-duplex. They aren't able to do that with SO-50 or LilacSat-2, due to the 2m transmitter desensing the 70cm receiver. As I also wrote last night, the Kenwood TH-D72A (not an "American" radio; it's made in Japan) does better than the KG-UV9D, but for AO-85 you could go with either radio. One advantage with the KG-UV9D is its price - less than $200 at most stores, compared with over $400 for the TH-D72A.
If you want to hear how I was hearing AO-85 with each of those radios, go back through my posts and visit my Dropbox space. Look for the MP3 files in each folder. That recording came from whatever radio I was using to work the pass. I put an audio splitter into the HT's speaker jack, and then fed audio to a small recorder and an earpiece. I wanted to have a record of what the radio heard, along with what a separate receiver (my SDR setup) heard from the satellite. You can play back those large WAV files if you download software like HDSDR, even if you don't have an SDR receiver or dongle.
For SO-50 and LilacSat-2, you could use the radio you already have to transmit to those satellites, and a KG-UV9D as the receiver, to make a full-duplex station for those two satellites. You could also program a group of memory channels for each of these satellites, but full-duplex operation is the way to go.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK
On Sat, Nov 28, 2015 at 10:56 AM, Skyler Fennell electricity440@gmail.com wrote:
Thanks for that information.
I am looking into the woxun radios, and see the kv9d at the top of your rank.
Is this an adequate radio for full duplex satellite operation, how far does it fall behind the American radios?
73 Skyler kd0whb
participants (2)
-
Patrick STODDARD (WD9EWK/VA7EWK) -
Skyler Fennell