Date   

Wierd Station on 1250 Today

Scott <scottmac1120@...>
 

Hey:

Thanks for the warm welcome, but, at the moment, I need some help. Has anybody heard something wierd on 1250 today? I'm listening on 1250 on my G8 right now and hearing nothing like the usual station, KIKZ Seminole, TX, on there right now. What I hear sounds very much like Arabic, with an English word here and there. It keeps switching languages. What I hear now sounds very much like German (with many "zh" sounds). Earlier it was Spanish. There has been music broadcasted here and there, in both Spanish and English. It's coming in with unbelievable clarity (only a little static; if it were in English, I could understand it perfectly). Now it's playing Regional Mexican music! Someone please help! They're skipping legal IDs, and it's making it very hard to identify. Thanks!

Scott
Hobbs, New Mexico

Grundig G8, Sony SRF-59


Re: DSP Soft Mute?

Roy <roy.dyball@...>
 

Farmerik

The soft mute is a feature of the Si4734 chip that allows the audio to be decreased by a predetermined amount when the signal you are listening to falls below a certain level. It's as if you just turned down the volume about 3 clicks. This feature being useful to most users works against us when we try to listen to distant stations.

You can pick this when listening to a weak signal that is hovering about 5db S/N. Because it is changing in signal level due to maybe atmospherics the soft mute will be cutting in and out changing the volume up and down. Its sort like rotating the volume wheel up and down very quickly. This chuffing sound is annoying. I listen every morning at dawn to my capitol city AM stations and in that hour after sun up the signal levels fade to nothing. The soft mute cutting in and out can easily be identified during this period.

Roy. 

 

 


--- In ultralightdx@..., "farmerik" wrote:
>
> I should have started a new thread for my question about exactly what is meant by the DSP 'soft mute' problem. I looked in the files section for an explanation, but couldn't find one. It could be in a DSP radio review though. Maybe it is well explained in an old post here, but I didn't find it that way either. Could someone explain or point me in the right direction. I have not been able to listen to most of the audio clips. I am too much of a computer idiot to know if it is because I have Linux instead of windows, or I just don't know how to get my computer to do that. When my son comes home to visit, if he has time, I'd like to get that working. For now I am looking for a written explanation. There are a lot of new terms being used on the group which I never heard when I was DXing many years ago. Others are probably unsure what they mean too. - FARMERIK
>


Re: G8 vs CR-1100 preliminary AM BCB report-FARMERIK

lrdheat
 

The soft mute occurs when tuned exactly on frequency on weak signals that vary between s/n's of 0, and s/n's that rise above zero...instead of a smooth rise or fall in the audible signal, the signal sounds like it is flickering. The set, if soft mute is the default mode (as it is on the G8 and PL-310), will semi mute the signal of a station that falls below (or rises above) a certain threshold of signal strength, resulting in the flickering of the audible signal.
 
Heatwave


--- On Sat, 1/2/10, farmerik wrote:

From: farmerik <farmerik@...>
Subject: [ultralightdx] Re: G8 vs CR-1100 preliminary AM BCB report-FARMERIK
To: ultralightdx@...
Date: Saturday, January 2, 2010, 9:49 AM

 

I used to use WICC as a test for a good radio in the daytime. It is much closer to Westport than I am in the Northeast of CT, while Westport and Naugatuck [WICC] are in the Southwest part of the state. Since you used to live in the area, I'll mention some call letters next time.

Maybe I need some help understanding exactly what the dreaded soft mute sounds like. Is it only a problem when tuned one or two Kc. off? Or is it the mute which happens before you couple an external loop, and you have to change frequency, and come back after the loop is in place? Maybe something else entirely? - FARMERIK

--- In ultralightdx@ yahoogroups. com, Richard Berler wrote:
>
> Thanks!
>  
> Also, check to see if there is a pumping on marginal-weak daytime signals (the dreaded soft mute).
>  
> I used to live in Westport, CT. From there, I needed a good radio to get WBZ and WPRO during the daytime, and to get WCAU, KYW, and WFIL?(560) from Philly.
>  
> Heatwave
> Streets of Laredo, TX!
>  
> --- On Fri, 1/1/10, farmerik >
>
> From: farmerik
> Subject: [ultralightdx] Re: G8 vs CR-1100 preliminary AM BCB report-FARMERIK
> To: ultralightdx@ yahoogroups. com
> Date: Friday, January 1, 2010, 7:21 PM
>
>
>  
>
>
>
> I'll see what I can do. I usually don't listen in the daytime.- FARMERIK
>
> --- In ultralightdx@ yahoogroups. com, Richard Berler wrote:
> >
> > Happy New Year!
> >  
> > Can you do some mid-day testing, and post your observations?
> >  
> > Thanks!
> >  
> > Heatwave
> >
> > --- On Thu, 12/31/09, farmerik wrote:
> >
> >
> > From: farmerik
> > Subject: [ultralightdx] G8 vs CR-1100 preliminary AM BCB report-FARMERIK
> > To: ultralightdx@ yahoogroups. com
> > Date: Thursday, December 31, 2009, 11:31 PM
> >
> >
> >  
> >
> >
> >
> > I've had the G8 for a couple months, since joining here, but just got my CR-1100 today. Both have the same DSP chip I believe. The CR only tunes in 10 Kc. steps on the AM BCB, but I believe it can be programed for 9 Kc. steps too.[You can not 'slope tune' it off a Kc. or two to escape an adjacent much stronger station.]
> >
> > The CR-1100 is rated by Tecsun at 0.5mv/M with its larger ferrite and the G8 is listed as 1mv/M. The CR-1100 is not really so much different than a modified DSP ULR with larger ferrite, but I don't think it qualifies for competition.
> >
> > I placed the two radios side by side, facing the same direction, running both on good alkaline batteries. I tuned three ten 'channel' bands, 700-790, 1000-1090 and 1500-1590, and took notes on each station I heard. I'll summarize here. The CR is noticeably better on about 50% of the frequencies, and about 1/3rd of those are substantial improvements. I got stations on all but 6 of the 30 frequencies on both radios, so it is a good night here in Connecticut.
> >
> > As expected, the audio bandwidth on the CR sounds noticeably wider, but what I didn't expect is that when ever there is back round noise, or a second weak station is also heard, it is much quieter on the CR. I expected wider selectivity to hear more noise and other stations not less. The narrower G8 bandwidth seems to hurt, NOT help with interference.
> >
> > Also, I looked at the meters for dBa and s/n. Both numbers scrolled all the time on strong and weak stations. The CR had +5 to +10 more units on the dBu scale on average, and sometimes the differences were much greater. The G8 ran +10 to +15 units on the s/n read out. I don't know what to make of that, but probably they are not 'calibrated' or 'standardized' , so it does not mean a thing. If anyone can explain it, I'm all ears.
> >
> > I tried the TERK with both radios, and as before with the G8, it can lower back round noise,but it does not seem to ever dig a weak station out of noise like it does on a cheap portable.
> >
> > -FARMERIK
> >
>



Re: New version of Tecsun PL-380

Chris Knight <chris@...>
 

Hopefully the newer version has soft mute completely disabled like the first known version did. After the first version, there was (at least) a second version. I believe the version I have is the second version which can be identified by the two screws in the battery compartment instead of just one (like Gary DeBock’s) and a sticker with the month and year (11/2009).

 

I was just inside my PL-380 looking around and noted that Tecsun placed silkscreen on the board which not only has reference designators, but part values as well. That may come in handy. ;-)

 

73,

 

Chris Knight (N0IJK)

 


From: ultralightdx@... [mailto:ultralightdx@...] On Behalf Of Robert S.Ross VA3SW
Sent: Saturday, January 02, 2010 12:41 PM
To: ultralightdx@...
Subject: Re: [ultralightdx] New version of Tecsun PL-380

 



Mark Roberts wrote:

 

At the end of the year just concluded, I purchased a Tecsun PL-380
from anon-co. Joyce responded and asked if I wanted the old version or
the new version! She indicated that, on the last day of the year,
Tecsun released a new version. So I've asked for the new version and
it is on its way.

Thought folks on the list would be interested in this news ....



Thanks for the info on this Mark.......but I guess it all depends on what they "Did" to the NEW VERSION???? Hopefully they made it better......

You'll have to let us know what the New Version has  that the Old Version doesn't!! Maybe we should email Joyce  and see if she can shed any light on the improvements.....or deletions????

Gary...are you familiar with this NEW Model yet?????

Thanks...ROB VA3SW

Robert S. Ross
London, Ontario CANADA


Re: New version of Tecsun PL-380

robert ross
 

Mark Roberts wrote:
 

At the end of the year just concluded, I purchased a Tecsun PL-380
from anon-co. Joyce responded and asked if I wanted the old version or
the new version! She indicated that, on the last day of the year,
Tecsun released a new version. So I've asked for the new version and
it is on its way.

Thought folks on the list would be interested in this news ....



Thanks for the info on this Mark.......but I guess it all depends on what they "Did" to the NEW VERSION???? Hopefully they made it better......

You'll have to let us know what the New Version has  that the Old Version doesn't!! Maybe we should email Joyce  and see if she can shed any light on the improvements.....or deletions????

Gary...are you familiar with this NEW Model yet?????

Thanks...ROB VA3SW

Robert S. Ross
London, Ontario CANADA


New version of Tecsun PL-380

Mark Roberts
 

At the end of the year just concluded, I purchased a Tecsun PL-380
from anon-co. Joyce responded and asked if I wanted the old version or
the new version! She indicated that, on the last day of the year,
Tecsun released a new version. So I've asked for the new version and
it is on its way.

Thought folks on the list would be interested in this news ....


Re: New version of Tecsun PL-380

Gary DeBock
 

Hi Chris, Rob and Mark,
 
Well, it would be great if I could give you all the full details on the new version of the PL-380, but it's news to me. 
 
Having only two PL-380's here (one of which is a 7.5" loopstick model) I had just placed an order with Joyce on December 29th for more PL-380's to tinker with-- but she didn't tell me anything about a new version. Anyway, if Tecsun has changed the PL-380's AM performance in any way, I'll be happy to order a new version PL-380 for testing ASAP, and report to the group how it compares to our existing models.
 
Keep your fingers crossed about completely muting the soft mute!
 
73, Gary (in Puyallup, WA)
 
 
 

In a message dated 1/2/2010 12:02:10 P.M. Pacific Standard Time, chris@... writes:
 

Hopefully the newer version has soft mute completely disabled like the first known version did. After the first version, there was (at least) a second version. I believe the version I have is the second version which can be identified by the two screws in the battery compartment instead of just one (like Gary DeBock’s) and a sticker with the month and year (11/2009).

I was just inside my PL-380 looking around and noted that Tecsun placed silkscreen on the board which not only has reference designators, but part values as well. That may come in handy. ;-)

73,

Chris Knight (N0IJK)


From: ultralightdx@yahoogroups.com [mailto:ultralightdx@yahoogroups.com] On Behalf Of Robert S.Ross VA3SW
Sent: Saturday, January 02, 2010 12:41 PM
To: ultralightdx@yahoogroups.com
Subject: Re: [ultralightdx] New version of Tecsun PL-380



Mark Roberts wrote:

 

At the end of the year just concluded, I purchased a Tecsun PL-380
from anon-co. Joyce responded and asked if I wanted the old version or
the new version! She indicated that, on the last day of the year,
Tecsun released a new version. So I've asked for the new version and
it is on its way.

Thought folks on the list would be interested in this news ....



Thanks for the info on this Mark.......but I guess it all depends on what they "Did" to the NEW VERSION???? Hopefully they made it better......

You'll have to let us know what the New Version has  that the Old Version doesn't!! Maybe we should email Joyce  and see if she can shed any light on the improvements.....or deletions????

Gary...are you familiar with this NEW Model yet?????

Thanks...ROB VA3SW

Robert S. Ross
London, Ontario CANADA


Re: Coil Winding Advice

Phil Pasteur
 

I found this link for the J&J 2" waterproof tape:
(http://www.medicalsuppliesshop.com/product.cfm/hurl/Waterproof-2-x-10-yd-40-tape-each-roll.html)

It is 6.05 per roll sold in single roll quantities. Beware though, for two rolls the shiipng charge is about $7.50

Phil P.

--- In ultralightdx@..., "Jim Shaw" <jshaw1@...> wrote:

All,

This similar Amazon link is a little less expensive at $23 plus shipping for 6 rolls @ 2"x2.5 yds:

http://www.amazon.com/dp/B000GCOI1O/ref=asc_df_B000GCOI1O993990?smid=A2UILHLLDUMCAM&tag=shopzilla_mp_1030-20&linkCode=asn&creative=380341&creativeASIN=B000GCOI1O

Jim Shaw
AL7BA


DSP Soft Mute?

Rik
 

I should have started a new thread for my question about exactly what is meant by the DSP 'soft mute' problem. I looked in the files section for an explanation, but couldn't find one. It could be in a DSP radio review though. Maybe it is well explained in an old post here, but I didn't find it that way either. Could someone explain or point me in the right direction. I have not been able to listen to most of the audio clips. I am too much of a computer idiot to know if it is because I have Linux instead of windows, or I just don't know how to get my computer to do that. When my son comes home to visit, if he has time, I'd like to get that working. For now I am looking for a written explanation. There are a lot of new terms being used on the group which I never heard when I was DXing many years ago. Others are probably unsure what they mean too. - FARMERIK


Re: Mixed bag with the Air Core Antenna add-on to Tecsun P...

Phil Pasteur
 

I alos ordered some shorter ferrite Amidon type 61 bars. I got a 4" a 3'75" and a 7.5" bar ordered. I will be very intereseted to see what results others get.

Gary, how do you calculte the inductance of the coil, or do you just wrap and measure. I have an LCR meter, but I will have to check the frequency that it tests at.

Is there a formula out there that allows calculation of the inductance based upon the ferrite configuration and number of turns of Litz wire? If so can someone point me to the location for it?

Phil P.

--- In ultralightdx@..., D1028Gary@... wrote:

Hi Chris and Jim,
Both Roy and I have ordered some shorter type 61 bars
from Amidon for these testing purposes (and possibly Jim has, also). Nick
Hall-Patch has been running similar tests on the PL-380 with type 61
ferrite bars he already had on hand, but I'll let him report his results directly
(should he choose to do so).


Re: Mixed bag with the Air Core Antenna add-on to Tecsun P...

Gary DeBock
 

Hi Phil,
 
Thanks for your comments, and I'm happy that you are joining in the loopstick experimentation for the PL-310/380 DSP models.
 
There is of course a formula for determining the inductance of a conductor, namely
                                4l
L= 0.0002 [ 2.3 log (  ----  --  0.75)] uH 
                                d
 
where "L" is the inductance in microhenries, "l" is the length of the conductor in cm, and d is the diameter of the conductor. This formula is for a single wire, and does not apply for ferrite-wound coils (which undoubtedly will have a more complex formula). If you wish to calculate inductance this way, I certainly admire your dedication :-) Almost every experimenter I know simply uses their LCR meter to check coil inductance.
 
In the PL-310/380 loopstick experimentation, my own focus has been to empirically test different combinations of ferrite cores, Litz wires, coil 'Q" and inductance to find a combination that works well with the 4734 DSP chips. As I have shared with the group, the only combination found so far that was really had superb performance on all AM frequencies (in the PL-380) was the 7.5" Amidon type 61 ferrite bar wound with an 81-turn coil of 40/44 Litz wire (at 554 uh), as documented in the PL-380 external loopstick transplant article. This configuration has the near optimum 1:3 coil-to-bar length suggested by Ben Tongue for maximum coil "Q" (in the article linked by Jim Kearman in a recent message) and has the additional advantage of being mounted outside the cabinet (found by Nick to increase coil "Q" in his PL-380 experiments). The quality of the ferrite bar mix and Litz wire apparently also make a difference in this case. Consequently, the Si4734 chip in the PL-380 seems to provide great AM sensitivity across the AM band with this particular loopstick configuration, even though the inductance of 554 uh may not be within the Silicon Labs' printed chip specifications.
 
A shortcut to finding optimum coil inductance during loopstick testing is to use a "Slider" coil, after an experimental loopstick has been made and connected to the PL-310 (or PL-380). The coil is slid in search of a sharp audio reception peak on weak stations, which indicates the inductance providing maximum AM sensitivity in the DSP radio. As Roy has cautioned, the tuning must be shifted back and forth to confirm this peak, and the RSSI and S/N readings must be averaged out before any conclusions are made. The big challenge now is to find a shorter loopstick configuration that will work well as an internal loopstick replacement for the PL-310/380 stock loopsticks. Like you and other tinkerers, I have ordered a serious shipment from Amidon toward this end, as well as one from Dave Schmarder. It's great that this loopstick experimentation is proving so popular-- the excitement almost seems like something contagious :-)
 
73 and Good Luck,  Gary            
 
 
       
 

In a message dated 1/2/2010 10:35:13 A.M. Pacific Standard Time, ppasteur@q.com writes:
 

I alos ordered some shorter ferrite Amidon type 61 bars. I got a 4" a 3'75" and a 7.5" bar ordered. I will be very intereseted to see what results others get.

Gary, how do you calculte the inductance of the coil, or do you just wrap and measure. I have an LCR meter, but I will have to check the frequency that it tests at.

Is there a formula out there that allows calculation of the inductance based upon the ferrite configuration and number of turns of Litz wire? If so can someone point me to the location for it?

Phil P.

--- In ultralightdx@yahoogroups.com, D1028Gary@... wrote:
>
> Hi Chris and Jim,
>
Both Roy and I have ordered some shorter type 61 bars
> from Amidon for these testing purposes (and possibly Jim has, also). Nick
> Hall-Patch has been running similar tests on the PL-380 with type 61
> ferrite bars he already had on hand, but I'll let him report his results directly
> (should he choose to do so).


RJR AM Jamaica

jim_kr1s <jkearman@...>
 

I think they are gone from AM. Haven't been able to copy them from South
Florida. The RJR official site, http://rjrgroup.com/index.php , doesn't
list any AMers, and there's no mention of anything but cable, TV and FM
in their 20080-2009 annual report.

Could be a good place for an AM DXpedition!

73,

Jim, KR1S


Re: G8 vs CR-1100 preliminary AM BCB report-FARMERIK

Rik
 

I used to use WICC as a test for a good radio in the daytime. It is much closer to Westport than I am in the Northeast of CT, while Westport and Naugatuck [WICC] are in the Southwest part of the state. Since you used to live in the area, I'll mention some call letters next time.

Maybe I need some help understanding exactly what the dreaded soft mute sounds like. Is it only a problem when tuned one or two Kc. off? Or is it the mute which happens before you couple an external loop, and you have to change frequency, and come back after the loop is in place? Maybe something else entirely? - FARMERIK

--- In ultralightdx@..., Richard Berler <lrdheat@...> wrote:

Thanks!
 
Also, check to see if there is a pumping on marginal-weak daytime signals (the dreaded soft mute).
 
I used to live in Westport, CT. From there, I needed a good radio to get WBZ and WPRO during the daytime, and to get WCAU, KYW, and WFIL?(560) from Philly.
 
Heatwave
Streets of Laredo, TX!
 
--- On Fri, 1/1/10, farmerik <farmerik@...> wrote:


From: farmerik <farmerik@...>
Subject: [ultralightdx] Re: G8 vs CR-1100 preliminary AM BCB report-FARMERIK
To: ultralightdx@...
Date: Friday, January 1, 2010, 7:21 PM


 



I'll see what I can do. I usually don't listen in the daytime.- FARMERIK

--- In ultralightdx@ yahoogroups. com, Richard Berler <lrdheat@ > wrote:

Happy New Year!
 
Can you do some mid-day testing, and post your observations?
 
Thanks!
 
Heatwave

--- On Thu, 12/31/09, farmerik <farmerik@ .> wrote:


From: farmerik <farmerik@ .>
Subject: [ultralightdx] G8 vs CR-1100 preliminary AM BCB report-FARMERIK
To: ultralightdx@ yahoogroups. com
Date: Thursday, December 31, 2009, 11:31 PM


 



I've had the G8 for a couple months, since joining here, but just got my CR-1100 today. Both have the same DSP chip I believe. The CR only tunes in 10 Kc. steps on the AM BCB, but I believe it can be programed for 9 Kc. steps too.[You can not 'slope tune' it off a Kc. or two to escape an adjacent much stronger station.]

The CR-1100 is rated by Tecsun at 0.5mv/M with its larger ferrite and the G8 is listed as 1mv/M. The CR-1100 is not really so much different than a modified DSP ULR with larger ferrite, but I don't think it qualifies for competition.

I placed the two radios side by side, facing the same direction, running both on good alkaline batteries. I tuned three ten 'channel' bands, 700-790, 1000-1090 and 1500-1590, and took notes on each station I heard. I'll summarize here. The CR is noticeably better on about 50% of the frequencies, and about 1/3rd of those are substantial improvements. I got stations on all but 6 of the 30 frequencies on both radios, so it is a good night here in Connecticut.

As expected, the audio bandwidth on the CR sounds noticeably wider, but what I didn't expect is that when ever there is back round noise, or a second weak station is also heard, it is much quieter on the CR. I expected wider selectivity to hear more noise and other stations not less. The narrower G8 bandwidth seems to hurt, NOT help with interference.

Also, I looked at the meters for dBa and s/n. Both numbers scrolled all the time on strong and weak stations. The CR had +5 to +10 more units on the dBu scale on average, and sometimes the differences were much greater. The G8 ran +10 to +15 units on the s/n read out. I don't know what to make of that, but probably they are not 'calibrated' or 'standardized' , so it does not mean a thing. If anyone can explain it, I'm all ears.

I tried the TERK with both radios, and as before with the G8, it can lower back round noise,but it does not seem to ever dig a weak station out of noise like it does on a cheap portable.

-FARMERIK


Re: BCmapII

Russ Edmunds <wb2bjh@...>
 

I have used printouts from the older version of BCMap for Graveyards to keep track visually of what I've heard, but only by using a highlighter on the call letters. I would imagine coloring in the circles or even the outlines would get hard to read very quickly.

It was both a lot of work to do this update and also a lot of convincing to convince Jim it was worthwhile. While a suggestion such as this is interesting, it would also be another significant effort, and given that no small number of his users are in broadcasting and use it for business purposes, it probably isn't something which would receive universal demand.


Russ Edmunds
Blue Bell, PA ( 360' ASL )
[15 mi NNW of Philadelphia]
40:08:45N; 75:16:04W, Grid FN20id

FM: Yamaha T-80 & Onkyo T-450RDS w/ APS9B @15'
AM: Modified Sony ICF 2010 barefoot


--- On Sat, 1/2/10, John H. Bryant wrote:

From: John H. Bryant
Subject: Re: [ultralightdx] BCmapII
To: ultralightdx@...
Date: Saturday, January 2, 2010, 6:39 AM

 

Gary,

THANKS!!!  The newer version of BC Maps II is a true wonder.  If you print a hard copy of a frequency, you could then color in the coverage areas that you have already heard to give yourself a DX planning tool.  That is the technique that I just wrote about in the article on Using the NRC Antenna Pattern Book as a Serious DX Tool!  I wonder if Jim will be able to take that step - coloring the coverage area of heard stations - electronically? ??  In any case, BC Maps II is a wonder!

John Bryant
Stillwater, OK
WinRadio G313e + Ultralights
Wellbrook Phased Array






At 03:38 AM 1/2/2010 +0000, you wrote:

 

Great news, folks. Jim Tonne's BCmap software has been upgraded, and now includes FCC data from 12/1/09.



Nova Scotia UL Report

John Cereghin <jcereghin@...>
 

After driving for 22 hours straight from Delaware to Nova Scotia on
New Year's Eve, we made it to my in-laws place in Greenwood, Nova
Scotia. Snow everywhere up here! Anyway, the PL-310 has been busy,
checking on Newfoundland stations and seeing what I can log barefoot.
A few logs from January 1:

540 CBT Grand Falls, Newfoundland, CBC, weakly
620 WZON Bangor ME, sports
740 CHCM, Marystown NF, IDs with VOCM, ads for Marystown Mall
1310 WLOB Portland ME, talk
820 WNYC New York NY, nice ID and NPR programming. A rather tough log
in Delaware
1520 WIZZ Greenfield MA, standards
1570 WNSH Beverly MA, ID and weather for the Merrimac Valley
1200 CFGO Ottawa ON, Ottawa 67s hockey
990 CBY, Corner Brook, Newfoundland CBC
1215 Absolute Radio (?), England with pop mx and another station with
what sounded like English talk but with very low audio, couldn’t ID
1715. First time I've heard two separate stations on 1215! This was
the only TA in besides 765 below.
765 Weak with female vocals, Germany? 1730

John Cereghin
Greenwood NS


Re: BCmapII

John H. Bryant <bjohnorcas@...>
 

Gary,

THANKS!!!  The newer version of BC Maps II is a true wonder.  If you print a hard copy of a frequency, you could then color in the coverage areas that you have already heard to give yourself a DX planning tool.  That is the technique that I just wrote about in the article on Using the NRC Antenna Pattern Book as a Serious DX Tool!  I wonder if Jim will be able to take that step - coloring the coverage area of heard stations - electronically???  In any case, BC Maps II is a wonder!

John Bryant
Stillwater, OK
WinRadio G313e + Ultralights
Wellbrook Phased Array






At 03:38 AM 1/2/2010 +0000, you wrote:
 

Great news, folks. Jim Tonne's BCmap software has been upgraded, and now includes FCC data from 12/1/09.


Re: G8 vs CR-1100 preliminary AM BCB report-FARMERIK

lrdheat
 

Thanks!
 
Also, check to see if there is a pumping on marginal-weak daytime signals (the dreaded soft mute).
 
I used to live in Westport, CT. From there, I needed a good radio to get WBZ and WPRO during the daytime, and to get WCAU, KYW, and WFIL?(560) from Philly.
 
Heatwave
Streets of Laredo, TX!
 

--- On Fri, 1/1/10, farmerik wrote:

From: farmerik
Subject: [ultralightdx] Re: G8 vs CR-1100 preliminary AM BCB report-FARMERIK
To: ultralightdx@...
Date: Friday, January 1, 2010, 7:21 PM

 
I'll see what I can do. I usually don't listen in the daytime.- FARMERIK

--- In ultralightdx@ yahoogroups. com, Richard Berler wrote:
>
> Happy New Year!
>  
> Can you do some mid-day testing, and post your observations?
>  
> Thanks!
>  
> Heatwave
>
> --- On Thu, 12/31/09, farmerik wrote:
>
>
> From: farmerik
> Subject: [ultralightdx] G8 vs CR-1100 preliminary AM BCB report-FARMERIK
> To: ultralightdx@ yahoogroups. com
> Date: Thursday, December 31, 2009, 11:31 PM
>
>
>  
>
>
>
> I've had the G8 for a couple months, since joining here, but just got my CR-1100 today. Both have the same DSP chip I believe. The CR only tunes in 10 Kc. steps on the AM BCB, but I believe it can be programed for 9 Kc. steps too.[You can not 'slope tune' it off a Kc. or two to escape an adjacent much stronger station.]
>
> The CR-1100 is rated by Tecsun at 0.5mv/M with its larger ferrite and the G8 is listed as 1mv/M. The CR-1100 is not really so much different than a modified DSP ULR with larger ferrite, but I don't think it qualifies for competition.
>
> I placed the two radios side by side, facing the same direction, running both on good alkaline batteries. I tuned three ten 'channel' bands, 700-790, 1000-1090 and 1500-1590, and took notes on each station I heard. I'll summarize here. The CR is noticeably better on about 50% of the frequencies, and about 1/3rd of those are substantial improvements. I got stations on all but 6 of the 30 frequencies on both radios, so it is a good night here in Connecticut.
>
> As expected, the audio bandwidth on the CR sounds noticeably wider, but what I didn't expect is that when ever there is back round noise, or a second weak station is also heard, it is much quieter on the CR. I expected wider selectivity to hear more noise and other stations not less. The narrower G8 bandwidth seems to hurt, NOT help with interference.
>
> Also, I looked at the meters for dBa and s/n. Both numbers scrolled all the time on strong and weak stations. The CR had +5 to +10 more units on the dBu scale on average, and sometimes the differences were much greater. The G8 ran +10 to +15 units on the s/n read out. I don't know what to make of that, but probably they are not 'calibrated' or 'standardized' , so it does not mean a thing. If anyone can explain it, I'm all ears.
>
> I tried the TERK with both radios, and as before with the G8, it can lower back round noise,but it does not seem to ever dig a weak station out of noise like it does on a cheap portable.
>
> -FARMERIK
>



BCmapII

Gary Kinsman
 

Great news, folks. Jim Tonne's BCmap software has been upgraded, and now includes FCC data from 12/1/09.

http://tonnesoftware.com/bcmap2.html


Re: Mixed bag with the Air Core Antenna add-on to Tecsun PL310

jim_kr1s <jkearman@...>
 

--- In ultralightdx@..., "Chris Knight" <chris@...> wrote:

The MW band is a pretty large swath of real estate for a single fixed coil to cover.
Everything was swell until they added X band! But I think SiLabs guarantees it will tune the US AM BC band with one coil. If the range of inductances is correct, that varactor has a wider range than any commercial discrete varactor I know of.

By virtue of the higher reactance at 1700 kHz, you're going to get more Q up there, so if the varactor just wheezes its way to the top, it should work pretty well. A given capacitance range will always tune the same number of octaves no matter the inductance. Assuming the chip can tune 530-1710, a 3.23 ratio, it should almost cover the 153-513 kHz LW band. You'd have to sacrifice a few kHz, but chances are the varactor can do a little better. But -- the inductance to resonate with 350 pF at 153 kHz is a whopping 3092 uH! No wonder the little guys don't hear well on LW. Even with a larger winding you'd have to add some loading inductance to make it resonate. You'd probably need about 1500-2000 uH, and a high-Q coil would be rather large. I'm thinking of how large those old 2.5-mH (2500-uH) National rf chokes were, and they had lousy Q by design. (By the way, those old chokes are a good source of fine Litz wire, if you unwind them carefully.)

Here's where your plug-in coils would solve the problem! I think you could get 3000 uH on a 7.5-inch rod.

I also think Tecsun should fly us all over for some Szechuan chicken, a walk on the Great Wall, and a consult on their next model!

73,

Jim, KR1S


Re: Mixed bag with the Air Core Antenna add-on to Tecsun PL310

Chris Knight <chris@...>
 

Jim,

I thought about the slide switch and believe this could be the right answer
for the reasons you mentioned. The MW band is a pretty large swath of real
estate for a single fixed coil to cover. Another good method of implementing
a change of inductance for lower band (and LW) would be the ability to
easily swap coils. I was thinking of using speaker terminals to make it
"plug-and-play"
http://www.radioshack.com/product/index.jsp?productId=2103795 . A person
could wind coils for different portions of the MW and LW bands and swap them
out easily. I'm using this technique with a 0-365pF variable cap in a
plastic project enclosure that can be swapped among loop antennas.

73,

Chris (N0IJK)

-----Original Message-----
From: ultralightdx@... [mailto:ultralightdx@...] On
Behalf Of jim_kr1s
Sent: Friday, January 01, 2010 5:47 PM
To: ultralightdx@...
Subject: [ultralightdx] Re: Mixed bag with the Air Core Antenna add-on to
Tecsun PL310



--- In ultralightdx@..., "Chris Knight" <chris@...> wrote:


I wonder what would happen if you went from 554uH down to 350uH in this
case (PL-310)? If you have already tried it, please let me know. I'm also
wondering what variations of stray PCB capacitance we can expect from these
Chinese manufacturers.

Good analysis, Chris. I think the length of the leads from antenna to board
probably contribute 3-5 pF by themselves. It appears the maximum capacitance
the chip's varactor can achieve is between 325 and 375 pF. Let's say 350 pF.
Scott was saying 270 uH was about the max for the G8. For the sake of
discussion and uniformity across models, let's say 270 uH and 325 pF maximum
C. That combination will resonate at 537 kHz. If you minimized stray
capacitance then, a 330-uH coil as supplied by Tecsun could resonate across
the US MW band. The problem with Tecsun antennas at MW is probably losses in
the core material vs -61, rather than inductance.

At the low end of the band where it can be resonated, there is a clear
technical advantage to using a larger inductance. The reactance of the coil
increases with more turns, more rapidly than does the ohmic resistance. The
"Q" is calculated by dividing reactance by resistance. If reactance rises
faster than resistance as inductance is increased, then a larger coil will
have higher Q. But to obtain the benefit of this Q, the coil must be
resonated by the tuning capacitance. (Reactance and resistance are both
measured in ohms; check Wikipedia or a copy of the ARRL Handbook for Radio
Amateurs at your local library for more info on the differences.)

It doesn't appear that the range of capacitance available will allow a
single antenna coil to resonate on both MW and LW. A 554-uH coil could
resonate down to 375 kHz or so; as you note, however, it won't resonate at
the high end of the MW band. A second coil and a tiny slide switch, to
select one or both coils, could do the trick.

73,

Jim, KR1S