Date   

Re: Filter width on DSP radios

seta <michael.setaazul@...>
 

10 kHz channel spacing, but with two 5.1 kHz sidebands.
There must be a good reason for this - no?
And how do adjacent channels sound in Canada?

Michael

----- Original Message --------------------------------------------------

From: "dhsatyadhana"

Hi Marc:


US signals are required to fit within a 10.2 khz total bandwidth, meaning that
it extends plus/minus 5.1 khz on either side, thus "sideband". As a result,
treble response is basically limited to 5.1 khz (it used to be 7.5 khz, and still is
in Canada, which is why some Canadian stations sound a lot better IMO)


Re: Filter width on DSP radios

Kevin Schanilec
 

Hi Marc:

It's coming from 740. Broadcast signals are dual sideband, meaning that there is essentially identical information on both the upper sideband. US signals are required to fit within a 10.2 khz total bandwidth, meaning that it extends plus/minus 5.1 khz on either side, thus "sideband". As a result, treble response is basically limited to 5.1 khz (it used to be 7.5 khz, and still is in Canada, which is why some Canadian stations sound a lot better IMO)

In the case of a domestic on 740, their lower sideband extends between 735 and 740, meaning that a TP on 738 is being severely trounced upon. However, the 738 itself has a lower sideband from 733 to 738, so tuning down to 737 or even 736 gets you farther away from 740 while listening to 738's lower sideband. There will still be some of 740's lower sideband mushing things up, but it will be diminished compared to tuning to the TP right on 738.

Hope this helps - Kevin

--- In ultralightdx@yahoogroups.com, Marc Coevoet <sintsixtus@...> wrote:

Op 19-12-10 22:15, dhsatyadhana schreef:
Hi Gary:


At the beach last time listening to split frequency targets, I did some
comparisons between DSP filtering and the outstanding 2.4 khz Murata
filter that has found its way into a lot of Eton e100's and CCrane
SWP's. The Murata is tighter than the 1 khz (2 khz total) filter on the
DSP radios, so kudos to Murata for still having the best filtering. For
instance, listening to 738 under a domestic on 740, the Murata has less
slop when the receiver is detuned by a khz to 737. So, the 1 khz DSP
setting might be better compared to a 2.8 khz "regular" filter - still
pretty darn good.

I am not sure is the slop coming from the 740Khz station, or is the slop
coming from the detoriation of all signals?

Marc

--
What's on Shortwave guide: choose an hour, go!
http://shortwave.tk
700+ Radio Stations on SW http://swstations.tk
300+ languages on SW http://radiolanguages.tk


Re: Filter width on DSP radios

Marc Coevoet
 

Op 19-12-10 22:15, dhsatyadhana schreef:
Hi Gary:


At the beach last time listening to split frequency targets, I did some
comparisons between DSP filtering and the outstanding 2.4 khz Murata
filter that has found its way into a lot of Eton e100's and CCrane
SWP's. The Murata is tighter than the 1 khz (2 khz total) filter on the
DSP radios, so kudos to Murata for still having the best filtering. For
instance, listening to 738 under a domestic on 740, the Murata has less
slop when the receiver is detuned by a khz to 737. So, the 1 khz DSP
setting might be better compared to a 2.8 khz "regular" filter - still
pretty darn good.

I am not sure is the slop coming from the 740Khz station, or is the slop coming from the detoriation of all signals?

Marc

--
What's on Shortwave guide: choose an hour, go!
http://shortwave.tk
700+ Radio Stations on SW http://swstations.tk
300+ languages on SW http://radiolanguages.tk


Re: Filter width on DSP radios

Gary Kinsman
 

Thanks for your explanation, Kevin.

--- In ultralightdx@yahoogroups.com, "dhsatyadhana" <dhsatyadhana@...> wrote:

Hi Gary:

You've got it spot-on: the DSP bandwidth is specified per sideband, not for the whole thing like most filters. So, the 1 khz bandwidth is actually a 2 khz (total) in normal parlance.

At the beach last time listening to split frequency targets, I did some comparisons between DSP filtering and the outstanding 2.4 khz Murata filter that has found its way into a lot of Eton e100's and CCrane SWP's. The Murata is tighter than the 1 khz (2 khz total) filter on the DSP radios, so kudos to Murata for still having the best filtering. For instance, listening to 738 under a domestic on 740, the Murata has less slop when the receiver is detuned by a khz to 737. So, the 1 khz DSP setting might be better compared to a 2.8 khz "regular" filter - still pretty darn good.

Since the 1 khz DSP filter does allow a little more signal through, one can detune by 2 khz (i.e., down to 736) on the Tecsuns sometimes, and get a better overall result than the Murata de-tuned by only a single khz. The limiting factor is whether or not there is still enough carrier frequency to modulate the signal: otherwise, the Donald Duck distorted audio results. This requires either a healthy signal for the desired target (i.e., a near-local), or the use of a regenerative loop like the Super SAT which when tuned to the carrier frequency supplies the carrier that the DSP filter is otherwise largely cutting off. Using a regen loop like this, tight trans-oceanic targets (like 729 under a 730 khz domestic) are much better IMO. The Murata filter is just too tight to allow this.

Thanks - Kevin


Re: Filter width on DSP radios

Kevin Schanilec
 

Hi Gary:

You've got it spot-on: the DSP bandwidth is specified per sideband, not for the whole thing like most filters. So, the 1 khz bandwidth is actually a 2 khz (total) in normal parlance.

At the beach last time listening to split frequency targets, I did some comparisons between DSP filtering and the outstanding 2.4 khz Murata filter that has found its way into a lot of Eton e100's and CCrane SWP's. The Murata is tighter than the 1 khz (2 khz total) filter on the DSP radios, so kudos to Murata for still having the best filtering. For instance, listening to 738 under a domestic on 740, the Murata has less slop when the receiver is detuned by a khz to 737. So, the 1 khz DSP setting might be better compared to a 2.8 khz "regular" filter - still pretty darn good.

Since the 1 khz DSP filter does allow a little more signal through, one can detune by 2 khz (i.e., down to 736) on the Tecsuns sometimes, and get a better overall result than the Murata de-tuned by only a single khz. The limiting factor is whether or not there is still enough carrier frequency to modulate the signal: otherwise, the Donald Duck distorted audio results. This requires either a healthy signal for the desired target (i.e., a near-local), or the use of a regenerative loop like the Super SAT which when tuned to the carrier frequency supplies the carrier that the DSP filter is otherwise largely cutting off. Using a regen loop like this, tight trans-oceanic targets (like 729 under a 730 khz domestic) are much better IMO. The Murata filter is just too tight to allow this.

Thanks - Kevin

--- In ultralightdx@yahoogroups.com, "gkinsman1" <gkinsman@...> wrote:

Hello all,

I noticed that on my PL-380, I can detune up to one filter width and still get good sound quality. For example, if I'm listening to 1070 kHz with the 2 kHz filter, I can tune as low as 1068 kHz or as high as 1072 kHz.

In the past, I've always used the rule that you can detune up to one half the filter width. This is how is works with my Satellit 800 and Icom R75 for example. With the 4 kHz filter selected on the Sat 800, I can detune by 2 kHz.

This leads me to believe that on the Tecsun DSP radios, the specified filter width is half as wide as it is on my other radios. For example, the 2 kHz DSP filter is equivalent to a 4 kHz filter on my other radios.

On most of my radios the filter width is specified using both sidebands; on the DSP radio it appears to be specified using just one sideband. I always thought the former was the standard way of measuring filters. Is this not the case?

Regards,
Gary


Re: Roberts Sports 995 2-Band PLL Synthesised Personal Stereo Radio

bty49514 <michael.setaazul@...>
 

--- In ultralightdx@yahoogroups.com, "brian nsl" <brian.nsl@...> wrote:

. . . Are you saying that Maplin and Comet both sell Tecsun ????
That would surprise me from my search results.
72, Brian.
----------------------------------------------------

I got my Etón G8 from a Maplin store.

Michael


Filter width on DSP radios

Gary Kinsman
 

Hello all,

I noticed that on my PL-380, I can detune up to one filter width and still get good sound quality. For example, if I'm listening to 1070 kHz with the 2 kHz filter, I can tune as low as 1068 kHz or as high as 1072 kHz.

In the past, I've always used the rule that you can detune up to one half the filter width. This is how is works with my Satellit 800 and Icom R75 for example. With the 4 kHz filter selected on the Sat 800, I can detune by 2 kHz.

This leads me to believe that on the Tecsun DSP radios, the specified filter width is half as wide as it is on my other radios. For example, the 2 kHz DSP filter is equivalent to a 4 kHz filter on my other radios.

On most of my radios the filter width is specified using both sidebands; on the DSP radio it appears to be specified using just one sideband. I always thought the former was the standard way of measuring filters. Is this not the case?

Regards,
Gary


Re: Roberts Sports 995 2-Band PLL Synthesised Personal Stereo Radio

Brian
 

Peter,
        Are you saying that Maplin and Comet both sell Tecsun ????
That would surprise me from my search results.
                                              72, Brian.

----- Original Message -----
From: pe1etr
Sent: Sunday, December 19, 2010 11:25 AM
Subject: [ultralightdx] Re: Roberts Sports 995 2-Band PLL Synthesised Personal Stereo Radio

 

The Eton G8 aka Tecsun PL-300wt (£50) and Sony SRF-59 (£20)are both still available (I have both) via well-known UK retailers Maplin and Comet respectively.

Peter, Blackpool UK


Re: Roberts Sports 995 2-Band PLL Synthesised Personal Stereo Radio

Peter 1956
 

The Eton G8 aka Tecsun PL-300wt (£50) and Sony SRF-59 (£20)are both still available (I have both) via well-known UK retailers Maplin and Comet respectively.

Peter, Blackpool UK

--- In ultralightdx@yahoogroups.com, "brian nsl" <brian.nsl@...> wrote:

Jerry,
A nice looking radio and unlike most other ultralights one that is available
to UK residents.
The features / size almost match my Aiwa CR-D3 model of the 1990's,
cost £40 ( $65 ) then.
72, Brian, G0NSL.


----- Original Message -----
From: Jerry
To: ultralightdx@yahoogroups.com
Sent: Thursday, December 16, 2010 9:40 PM
Subject: [ultralightdx] Roberts Sports 995 2-Band PLL Synthesised Personal Stereo Radio


New one - 1540 KXEL

Kevin Schanilec
 

Hi all:

This is a slam-dunk and/or pest in many parts of the country, but with a fairly strong local on the exact same bearing, KXEL has proven elusive here on ANY radio or antenna. At night, the local (KXPA) throws all of its 5kw at me from about 12 miles away, so the effective power is probably 10-15 kw or higher.

At any rate, it took a likely glitch in the local station's top-of-hour transition, which left a 5-second silent space, in which I got a perfect KXEL ID. This was on a Tecsun PL-360 with the DeBock 7.5" antenna mod.

Kevin S
Bainbridge Island, WA


File space here on the Group

Kevin Schanilec
 

Hi all:

The good news is that you all are hearing some great catches on your Ultralights and are sending in audio clips so that the rest of us can hear as well. The bad news is that audio clips can be fairly large in size, especially if recorded at high bit rates (over 100 kb/s).

We were getting quite low on file space here, so I took the liberty of converting some of the larger audio clips with high bit rates to a lower bit rate (but still more than sufficient for DX audio), and then reposted them with the same description and attributing them to the DXer who originally submitted them. We've now got some breathing room once again in the Files section. Thanks for your understanding on this.

We definitely want to hear what your hearing! I do request that you keep the bit rate down to 32 or 64 kb/s for posted audio clips. I would be happy to help you convert them if you're not familiar with audio conversion software - just drop me a line with the audio clip attached and I can convert it and send it back to you for posting here on the Group.

Thanks, and good DXing!

Kevin S
Moderator


Well, it's official I joined the National Radio Club..........................

Alex
 

Well, I took the plunge and went off to get the current edition of the NRC AM Radio Log the antenna pattern book and the sunset / sunrise charts . And thus in order to get the discount, I ended up getting a E-DXN membership. I've seen I some members from these AM radio boards. And I'm pleased to see that they even have a contest that involves a ULR radio class!!!

  The members only areas have a lot of interesting information that's appears to be updated weekly if not sooner.

  So if your in to AM DXing give them a visit at their website and order their publications or join. You'll be glad you did.

  Alex N8UCN / KOH8IG / SWLR-RN037   


Re: AM Query down for weekend

Alex
 

Bummer!!!! At least I got a copy of AM DX Log.

It's a valuable reference just the same.

Alex

--- In ultralightdx@yahoogroups.com, "ferrite61" <dxrx@...> wrote:

The FCC.com database webpage for AM radio stations is down for this weekend for scheduled maintanence. It is scheduled to be availible Monday Dec. 20th.

Paul S. in CT


AM Query down for weekend

ferrite61 <dxrx@...>
 

The FCC.com database webpage for AM radio stations is down for this weekend for scheduled maintanence. It is scheduled to be availible Monday Dec. 20th.

Paul S. in CT


Two New stations Logged

Kirk <kirk74601@...>
 

Just a few newbies to pass along today. All logged on Eton E-100 Slider w/ SAT.

620, KJOL, Grand Junction, CO, 2350 UTC,12/16/10. Pgm of rel mx and tlk. Several unmistakeable IDs near the TOH. Pretty good signal when they peaked. Fighting it out with a very strong CKRM.

TNX TO RICHARD ALLEN FOR THE TIP ON THIS NEXT ONE!
650, XERCG, Ciu. Acuna, CO, UTC, 12/18/10. Very tough copy due to QRM from the very strong CKOM, and also XETNT. They had much talk ment'g Coahuila. Hrd was sounded like an ID, "La Nueva Vida Radio..." That ID is tentative. At times they sounded like a discussion abt religion tho I can't be sure. ULR Sta #717, LAm Sta #134-

Also noted several other Canadian stations across the band. Very surprised I could hear very much from the south due to the northrn stations enhancements.

Take care amigos y amigas until next time.

Kirk Allen
Ponca City, OK


Re: New station 12-17-10

Kirk <kirk74601@...>
 

--- In ultralightdx@yahoogroups.com, "RichardA" <richarda@...> wrote:

I got lucky this morning and heard a new station.

It was 570 CKSW, Swift Current SK at 1319 with a barely audible, mostly unintelligible signal. But contrary to the rule, it peaked at 1326 with an ID "Local news, local weather, local sports, CKSW 570", before eventually fading under KLIF. (Station #788, SK #11)

Receiver was a Tecsun PL-360 with 7.5-inch loopstick attached.
Richard Allen
36°22'51"N / 97°26'35"W
(near Perry OK USA)
Great catch,Richard! I noticed signals were way up from the north country this morning. I had big signals from 650, CKOM, 630, CKRM amonth others.

73 to you, neighbor!

Kirk Allen
Ponca City, OK


New station 12-17-10

bbwrwy
 

I got lucky this morning and heard a new station.

It was 570 CKSW, Swift Current SK at 1319 with a barely audible, mostly unintelligible signal. But contrary to the rule, it peaked at 1326 with an ID "Local news, local weather, local sports, CKSW 570", before eventually fading under KLIF. (Station #788, SK #11)

Earlier I heard a weather report on 1280 with temperatures in Celsius. Most likely it was CJSL, Estevan SK. It was barely audible and eventually faded away under near-by KSOK.

Several other stations from the area were audible. Fair-to-good signalswere heard from 990 CBW and 1050 CKSB, Winnipeg MB, over an hour past sunrise.

Receiver was a Tecsun PL-360 with 7.5-inch loopstick attached.

Good DX,

Richard.

Richard Allen
36°22'51"N / 97°26'35"W
(near Perry OK USA)


Re: Roberts Sports 995 2-Band PLL Synthesised Personal Stereo Radio

Brian
 

Jerry,
         A nice looking radio and unlike most other ultralights one that is available
to UK residents.
The features / size almost match my Aiwa CR-D3 model of the 1990's,
cost £40 ( $65 ) then.
                                                  72, Brian, G0NSL.
 
 

----- Original Message -----
From: Jerry
Sent: Thursday, December 16, 2010 9:40 PM
Subject: [ultralightdx] Roberts Sports 995 2-Band PLL Synthesised Personal Stereo Radio


Re: Christmas Greetings from Down Under

Gary DeBock
 

Hi Tony,
 
Thanks for the Christmas greetings, and your astonishing X-band loggings from North America certainly inspire the holiday cheer!
 
While we are amazed at your DXing success in New Zealand, some of my most exciting loggings in 2010 came from Kiwi stations, including solid summer contacts of 603-Radio Waatea while on Oregon cliff sites overlooking the ocean. 603-Waatea had apparently never been heard by Grayland, Washington DXers with Perseus SDR's and beverages, but it was easy copy with a Tecsun PL-380 and 3' portable loop on a 100' cliff in Lincoln City, OR. Every time the simple ULR DXpedition gear was set up, the Kiwis would seem to steal the show. Have lots of fun this summer, Tony, and we will be eager to hear more of your loggings!
 
73, Gary    
 

In a message dated 12/16/2010 8:36:42 P.M. Pacific Standard Time, tonyzl@... writes:
 

Hi everyone,
What a great year this group has had, and I look forward to the innovations and developments in 2011. I think it's about time Tecsun shouted Gary a ride to China - and a cup of tea with Joyce en route !
As TP's fade out for US DXers we start our North American foray so the loops, EWE's and BOG's are lined up pointing NE and hopefully I'll get a bag full this summer. At the peak I can hear about 27 X band stations - it's amazing how far an overnight 1kw can go. Farthest east catches are WCNZ 1660 Marco Is FL and KVNS Brownsville TX 1700. Year round 1580 is the spot with KMIK and KBLA, and 1570 now has KUAU mixing with XERF - both dominated in June July by Nueva Q in Lima with b2b cumbia.

Thanks Gary and other posters - I'm learning something new every week from your practical posts.

All the best for the Festive season from NZ

Tony King


Re: #207

Brian Miller
 

Ha! No , 207 overall!

I'm the sole parent of a five year old boy. I don't have anywhere near the time needed to do that!

I meant to say that since I switched to using the t615 a week ago that I have logged stations number 200-2007 on it! Seven stations.

That may not sound like many but in my case, It's good times.



Since my last post I did log #208 - 1250 WLEM Emporium PA .



I've been DX'ing since March of this year, and ultralight DX'ing has been my introduction to DX'ing of any kind.

My previous 199 stations were logged on various Tecsuns an srf-59.

Brian

Berkley MI

--- In ultralightdx@yahoogroups.com, "dhsatyadhana" <dhsatyadhana@...> wrote:

Wow - 207 stations in about a week? That's quite a testament to the T615! No doubt we'll soon be hearing about #300.

Kevin S

--- In ultralightdx@yahoogroups.com, "Jerry" <brianalexmiller@> wrote:

Well, the SRF-T615 is everything everyone told me it was when I posted questions about it last week. Since then I have been DXing only with the Sony and have logged stations 200 through my 207th station earlier this evening:

Oldies 1250 WARE - Ware, MA around 22:05 local time (est)

Brian

Berkley MI USA