[amsat-bb] RTSystems has Software for Kenwood TH-D74a
jeff_griffin at comcast.net
Sun Dec 4 18:44:49 UTC 2016
Hi Patrick, Well I’m glad there is filtering added to the SSB frontend. I remember trying to use a TH-F6a to RX FO-20/29 years ago and the RX bandwidth was a show stopper. The recording option sounds like a real plus for portable ops...
73 Jeff kb2m
From: Patrick STODDARD (WD9EWK/VA7EWK)
Sent: Sunday, December 04, 2016 1:18 PM
To: Jeff ; amsat-bb at amsat.org
Subject: Re: [amsat-bb] RTSystems has Software for Kenwood TH-D74a
With the TH-D74, you get new features for receive filters. For SSB,
the high-cut value has possible options between 2.2 to 3.0 kHz. For CW
bandwidth, it can be specified values between 0.3 and 2.0 kHz. On
AM, the high-cut value can be between 3.0 and 7.5 kHz. This is, I
think, the sort of filtering that the TH-F6A sorely lacked.
Having this filtering makes the TH-D74's all-mode receiver work
reasonably well, especially as an SSB receiver for satellite
downlinks. I am comfortable with using my TH-D74A as an SSB
receiver in place of one of my FT-817NDs or an SDR receiver.
The TH-D74 also has an audio recording function, when a microSD
card is plugged into the radio. I used that to make recordings
of different passes I worked (FM, SSB, packet), and also testing
a Bluetooth headset with this radio. I posted those recordings
in the "TH-D74A" folder at http://dropbox.wd9ewk.net/ . If you want
to hear recordings from SSB satellites specifically, please
let me know and I can get you those file names.
I think Kenwood missed the mark a bit with this radio, not designing
it to have the cross-band full-duplex capability of the TH-D72
and TH-D7. Since the TH-D74A also operates on the 222 MHz band, it
is possible that Kenwood's engineers based the TH-D74 on the design
of the TH-F6A, but with lots of improvements and new features
that weren't possible with the older radio.
On Sun, Dec 4, 2016 at 5:55 PM, Jeff <kb2m at comcast.net> wrote:
Does it still have the 6k something + wide SSB frontend like the 10+ year old TH-F6a? I read Patrick's post about it and I don't remember any Kenwood rep at Dayton say it would do full duplex. I think Kenwood really missed the boat on this one.
73 Jeff kb2m
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