Date
1 - 20 of 24
Two new ultralights - Nov 2022
Emily Keene
I ordered the XDATA D219 just now. Normally, their radios are exceptional for their price point. We shall see...
Emily Keene, Pittsburgh, PA
On Dec 1, 2022 1:24 PM, Andre <strydenburg@...> wrote:
I see the XHDATA D-219 is available on the XHDATA website now, a mere $7. That's really tempting for a small, new toy.
Andre
Me too, just ordered it! $10, including shipping to South Africa. Let's see, I am actually quite excited to try it out. I think I might also order the Tecsun PL-320, seems to be exactly the same as the PL-330, but without USB, which I don't really use, so the PL-320 seems like a nice option for me. It does have a kickstand and external antenna input, which seem nice.
Andre
It is available on the XHDATA website in China. I have bought from them three times before, twice the orders arrived with no issue. The third one never arrived, but I did receive a refund from PayPal.
XHDATA D-219
Tecsun PL-320
XHDATA D-219
Tecsun PL-320
Max Italy
PL-320 tech specs. and feedback, enable google translator
https://detail.tmall.com/item_o.htm?id=688406670542
Tecsun forum, enable google translator
I found your post really interesting. As the radio has analogue tuning (despite being DSP), how is this impacted by turning steps (9 or 10khz).Hi,
Of course this is all speculation until performance and teardown evals are done on this new model - but realistically one would not expect new superhet models at this time and price point.
If this set is designed as were previous models, the "analogue tuning" is just an illusion, it is a mechanically controlled digital receiver.
The tip-off is in actual use, as the tuning experience is not continuous but rather jumps from one frequency to the next as the knob is turned.
The DSP chip performs all of the "radio" operations, and is simply fed commands from an external control (e.g. a potentiometer or rotary encoder for tuning).
Parameters such as frequency ranges, MW step, and such can be in firmware and/or controlled externally.
The CCrane EP Pro (a full size portable using the Si4734) is an excellent example of the downsides of distributing this kind of radio outside its intended market.
In the second production run, in response to customer demand, they brought out the DSP logic lines that control MW step onto a physical slide switch which is now mounted on the back panel, to allow the user to also select 9KHz steps outside North America.
mediumwavedx
Not sure many know this tip, but it's easy to determine whether an analog portable is the old style superhet "tuned with a capacitor + coil" or the new style using a DSP chip, tuned with a potentiometer.
Old style analog superhets dating back to the early days of radio necessarily use logarithmic tuning resulting in the display dial frequencies being scrunched closer together at the high end of the band.
Pseudo "analog" DSP-chipped radios use a linear 100K potentiometer to tune the chip, resulting in a linear frequency scale across the entire band.
So, for example, if you look at a detailed image of the radio's display scale and the physical distance between the numbers 600-1000 KHz is the same as the distance between 1200-1600 KHz, you have a DSP chip analog.
If the physical distance between 600-1000 KHz is much wider than the distance between 1200-1600 KHz, you have a traditional analog receiver.
Compare images of this D-219 to a Tecsun R9700DX after you zoom in a little, and you will see what I mean. The R9700DX is an old style superhet analog receiver. The top end of the MW band is scrunched together. The D-219 frequencies are evenly distributed. Even more evident, the CC Radio EP Pro with its even scale divisions all the way to 1710 identifies this radio as analog DSP.
Tuning steps on the DSP chips are software-determined, both in the pseudo analog models and the usual digital models like the PL-380, etc. In fact, neither the digitally displayed DSP radio or the analog DSPs are tuned by an external variable capacitor. The analog version, tuned with a potentiometer, polls the resistance of the pot at regular intervals to determine tuning, the digital version is tuned when the tuning encoder triggers a pulse to the DSP chip, at which point the chip software issues an AM_TUNE_FREQ up or down command at the selected frequency step.
-- Bill, WE7W near Rochester, NY
https://radio-timetraveller.blogspot.com
Hi Peter,
I think the step could be anything they decide, from 1 KHz on up. The basic minimal tuning step is 1 KHz. Practically, the step may just be 9 or 10 KHz. Even my $100 CC Radio EP Pro jumps immediately to each channel, in other words, it doesn't tune "through" each channel like an old analog receiver does.
But yes, ideally, the1 KHz step size might make tuning through a signal seem more normal if that could be accomplished.
--
Bill, WE7W near Rochester, NY
https://radio-timetraveller.blogspot.com
I think the step could be anything they decide, from 1 KHz on up. The basic minimal tuning step is 1 KHz. Practically, the step may just be 9 or 10 KHz. Even my $100 CC Radio EP Pro jumps immediately to each channel, in other words, it doesn't tune "through" each channel like an old analog receiver does.
But yes, ideally, the1 KHz step size might make tuning through a signal seem more normal if that could be accomplished.
--
Bill, WE7W near Rochester, NY
https://radio-timetraveller.blogspot.com
So ideally in this type of cheap radio the step would be 1Khz? That would then please all audiences.Probably, but it could be hard to integrate mechanically into a potentiometer-coupled slide-rule type analog dial which must also service the step rates of other frequency ranges.
Also it would take a lot of wheel turning to get across the dial.
The ideal solution might be a ganged set of coarse and fine tuning knobs but that adds extra gears, knobs, and cost.
Actually I think the solution that CCrane used on the 2nd-run EP Pro is ideal in that it uses a slide switch to mimic what the full digital sets accomplish with button presses.
--mike