Date   

Re: G8 signal strength meter

Roy <roy.dyball@...>
 

Jim you would really love the USB mod on the G8. You can completely turn the soft mute off and select the filter you want then disconnect it from the computer and use it in a normal manner away from the computer till power down and with good rechargeable batteries you can leave it on for days.

In some ways the G8 is superior to the PL-380 when set up on the computer. The Pl-380 still has a touch of soft mute. I turn the soft mute completely off with the software and the 1Khz filter sounds a bit clearer on the G8 as it has a different audio stage configuration and seems to be more punchy with a higher tone. I am really looking forward to trying out the 1.8Khz bandwidth and the 2.5Khz bandwidth, gradual roll off selections in the new Si4734-C40 ver40 firmware. I think the new PL-380 2009.9 ver2 may have the new chip but I don't think they have the new filter selection available.

You are probably better off with the clock selected because if you listen carefully on certain frequencies when you have the meter selected you can hear the local MCU perform the Received Signal Quality (RSQ) update. This is more noticeable with a larger loopstick.

Cheers Roy. 

 

 

--- In ultralightdx@..., "jim_kr1s" wrote:
>
>
> --- In ultralightdx@..., Tony Germanotta
> germanotta.tony@ wrote:
> >
> > So would you avoid the soft mute or the zero reading by merely keying
> in 1209 instead of 1210, for instance? Or by setting the step to 9Khz
> rather than 10 for transatlantic stations? It doesn't seem to do
> anything for me, but that would be a rather simple way to eliminate the
> soft mute, which doesn't seem to bother me nearly as much as most folks
> here. I am still amazed at what this little chip can do.
>
> The soft mute really gets annoying when there are two signals on the
> same frequency but slightly out of phase. If you're tuned to the
> station's frequency, whether on 9- or 10-kHz channel, and it's strong
> enough, the soft mute won't be a problem. But it can turn on even when
> you're right on the frequency if the station fades. Just as they ID, on
> the downward slope of a fade, the bloody soft mute turns on and makes it
> even harder to hear. Arrrrggggh.
>
> When DXing splits I start on-frequency, but sometimes go up or down 1
> kHz to get away from interference. I always use headphones, so even if
> the s-m goes on, there's usually enough audio. I find it more of a
> problem on crowded channels, like the Graveyards. Sounds like a steam
> locomotive high-balling it.
>
> Because I have the radio on a turntable I can't see the meters much of
> the time anyway, so I rarely bother with them when DXing. In fact,
> lately I've been keeping the display set to show UTC time, as my little
> UTC clock found its way back to the portable ham station container!
> (I've always logged in GMT/UTC.)
>
> 73,
>
> Jim, KR1S
> http://qrp.kearman.com.
>


Re: Damaged my Si4734

Roy <roy.dyball@...>
 

Thank you Scott for your generous offer. I have sent you an email with my address.

Thank you Jim and Steve for your offers.  This has to be one of the best groups I have ever come across.

Scott you are absolutely correct about grounding the line before soldering. "An ounce of prevention" as they say. One gets very blasé and when you have gotten away without the correct precautions dozens of times, you feel bullet proof. I have also been caught out on hot dry days with static. It has been hot and dry here in Australia over the past week with temperatures over 100 degrees F most days.

It was truly amazing the arc that the 660 Litz wire coil produced on the 7.5" rod and with freshly charged 2650MA NiMH batteries providing current into less than an ohm. It looked and sounded like RF.

Cheers Roy.

 

--- In ultralightdx@..., "sdwillingham" wrote:
>
>
>
>
> Sorry to hear that Roy. I guess it might be a smart precaution to
> short AMI to ground while soldering the antenna in.
>
> Shoot me an email with your shipping address. I'm sure I can find
> a replacement part around the lab here.
>
> I don't think that a C40 part is likely to work in the G8/PL-3XX
> radios until Tecsun ships it. (And I have no clue if, or when that
> might be.) From playing with my PL-300, I believe it is using
> a firmware 'patch'. So, although the C40 firmware should be
> backwards compatible, the radio (which expects a B20) will try to
> download patch code during the power-up process. Unfortunately,
> patch code is specific to the exact firmware revision, so the
> likely result is program corruption and CRC errors.
>
> -Scott-
>
> --- In ultralightdx@..., "Roy" roy.dyball@ wrote:
> >
> >
> > Hi All
> >
> > It had to happen after many multiple operations and hundreds of hours of
> > software development with my old faithful G8 I have damaged my Si4734
> > chip. I was sure that this was going to happen in the dozens of times I
> > made connections to the control lines. But no, a careless slip of a
> > Loopstick wire brought me undone.
> >
> > I was unsoldering one of the loopstick wires when the heat travelled so
> > quickly up the 660 strand Litz wire that it burnt my finger. 660 Litz is
> > really flexible and with a nice tinned end it is relatively heavy. It
> > seemed to fall across the circuit board snapping and popping till it
> > came to rest. A coil made from 660 Litz is very low resistance.
> >
> > Smoke was coming from the SW switching FET. Luckily I have one of these
> > and it was easy to replace. However the radio was deaf on AM with only a
> > bit of noise right at the bottom of the band, FM worked fine. To make
> > double sure I disconnected the switching diode thus eliminating the SW
> > pre amp this did not help. I also checked the AC coupling capacitor
> >
> > Connecting the radio to my software showed that on every station that
> > the varactor was showing max count and capacitance (6143) so it is not
> > tuning. I have a really small propane torch so it only took 30 seconds
> > to remove the chip from the circuit board ready for the new one.
> >
> > I figure this is a blessing in disguise as I really want to try out the
> > Ver40 firmware. The trouble is that those suppliers who stock the chip
> > only have Ver20 and with the stock numbers they have I don't think
> > they will be stocking Ver40 for a while. Has anybody in the group seen a
> > Si4734-C40 in their browsing for sale? I tried Mouser.com but they only
> > have the V20. Their price is good for the V20, about $15.00 but they
> > want $39.00 to ship an item 3mm square that is probably so light you
> > cannot way it.
> >
> > I cannot speak highly enough about the Si4734 chip; it is a sturdy well
> > protected little chip. This was my fault so be careful when working with
> > 660 Litz wire. Also if ever you remove the Si4734 from the circuit board
> > go out of your way to put it some ware safe as I have already misplaced
> > the old one. I had it on my bench and when I looked for it, it was gone.
> > It cannot have gone far and should turn up.
> >
> > Cheers Roy.
> >
>


Re: G8 signal strength meter

jim_kr1s <jkearman@...>
 


--- In ultralightdx@..., Tony Germanotta wrote:
>
> So would you avoid the soft mute or the zero reading by merely keying in 1209 instead of 1210, for instance? Or by setting the step to 9Khz rather than 10 for transatlantic stations? It doesn't seem to do anything for me, but that would be a rather simple way to eliminate the soft mute, which doesn't seem to bother me nearly as much as most folks here. I am still amazed at what this little chip can do.

The soft mute really gets annoying when there are two signals on the same frequency but slightly out of phase. If you're tuned to the station's frequency, whether on 9- or 10-kHz channel, and it's strong enough, the soft mute won't be a problem. But it can turn on even when you're right on the frequency if the station fades. Just as they ID, on the downward slope of a fade, the bloody soft mute turns on and makes it even harder to hear. Arrrrggggh.

When DXing splits I start on-frequency, but sometimes go up or down 1 kHz to get away from interference. I always use headphones, so even if the s-m goes on, there's usually enough audio. I find it more of a problem on crowded channels, like the Graveyards. Sounds like a steam locomotive high-balling it.

Because I have the radio on a turntable I can't see the meters much of the time anyway, so I rarely bother with them when DXing. In fact, lately I've been keeping the display set to show UTC time, as my little UTC clock found its way back to the portable ham station container! (I've always logged in GMT/UTC.)

73,

Jim, KR1S
http://qrp.kearman.com. 


Re: G8 signal strength meter

Tony Germanotta
 

So would you avoid the soft mute or the zero reading by merely keying in 1209 instead of 1210, for instance? Or by setting the step to 9Khz rather than 10 for transatlantic stations? It doesn't seem to do anything for me, but that would be a rather simple way to eliminate the soft mute, which doesn't seem to bother me nearly as much as most folks here. I am still amazed at what this little chip can do.


On Jan 27, 2010, at 12:51 PM, sdwillingham wrote:

 



Hi Tony,

I am glad you find the discussion interesting. Sometimes I
worry about alienating the non-tech group members with too
much technical stuff vs dxing strategies, techniques, and
results.

>> "Does the radio somehow know the center of the signal I
>> am shooting for?"

Actually, the problem is that it doesn't know the center you
are shooting for when you tune to a different one!

Your question is a very good one and the answer is non-obvious
to anyone without inside information on the chip's design.
Essentially, the chip needs to know the desired carrier frequency
in order to do its 'smart' SNR signal processing and calculation.
When you off-tune, the chip no longer 'sees' the carrier where
you told it to 'look'. Under this condition, the processor
considers the SNR calculation to be invalid and returns a 0 dB
result.

By the way, this is part of the issue dxer's have with soft-mute.
The soft-mute calculation is based on the measured SNR. So when
you off-tune, the SNR goes to zero and soft-mute (if enabled)
kicks in.

Cheers,
Scott

--- In ultralightdx@yahoogroups.com, Tony Germanotta tony@...> wrote:
>
> Thanks Jim and Scott for the info. This is fascinating stuff for a non-techie like me. I have a question, though. When I offtune my PL-310 to one side or another of a frequency, not only does the signal strength drop a few notches on the volume knob, I always get a 0 SNR reading, no matter how well the station is coming through, no matter how tight the bandwidth. Does the radio somehow know the center of the signal I am shooting for? Of course, it really doesn't matter, the important thing is intelligibility. But it has me wondering just how smart this chip really is. Is it reading my mind, or just my WRTV Handbook?
>
> On Jan 26, 2010, at 11:17 PM, sdwillingham wrote:
>
> >
> > Jim gives an excellent explanation of the RSSI and SNR indicators.
> > Here are some further comments for more technical readers.
> >
> > 1) The abbreviation RSSI stands for "Received Signal Strength
> > Indicator", not "Relative . . ." Jim correctly emphasizes
> > that this strength refers to the LNA input voltage, not
> > electromagnetic field strength.
> >
> > 2) The signal-to-noise ratio Jim describes refers to signal strength
> > compared to the noise generated by the radio circuitry. The SNR
> > metric from the Si4734 is more sophisticated than that. If one
> > substitutes a short-circuit across the AM antenna terminals, he
> > will see the RSSI drop to 2-5 dBuV. With an antenna connected
> > and "between stations", the RSSI can be 30 or more dBuV. Yet the
> > Si4734 does not report the SNR as 25 dB, i.e. the signal strength
> > above the receiver noise floor. Instead, the chip reports a
> > metric measuring the signal strength relative to atmospheric
> > noise and interference. Of course, if the atmospheric noise is
> > low enough (or antenna gain is inadaquate), the SNR calculation
> > will reflect the receiver circuit's noise floor. I wish I
> > could give more detail about the calculation, but I believe that
> > is proprietary information.
> >
> > Cheers,
> > Scott
> >
> >
>



Re: latest logs

jim_kr1s <jkearman@...>
 


--- In ultralightdx@..., Allen Willie
>
> Decent conditions last night and early this morning in the North Atlantic with these logs and 1 new one
>
> 850 khz - WFTL - West Palm Beach, Florida 1/27/10 9:50 UTC w/ news and talk, mentions of Florida

> SRF-M37V barefoot

Ah, hahaha, we hackers think we are so cool with our modified Tecsuns, and you are doing great things with that barefoot radio! WFTL is one of my local pests, about 30 miles (50 km) away. I'm glad someone got some use out of it! :)

Always enjoy reading others' loggings.

73,

Jim, KR1S
http://qrp.kearman.com/    


Re: G8 signal strength meter

sdwillingham
 

Hi Tony,

I am glad you find the discussion interesting. Sometimes I
worry about alienating the non-tech group members with too
much technical stuff vs dxing strategies, techniques, and
results.

"Does the radio somehow know the center of the signal I
am shooting for?"
Actually, the problem is that it doesn't know the center you
are shooting for when you tune to a different one!

Your question is a very good one and the answer is non-obvious
to anyone without inside information on the chip's design.
Essentially, the chip needs to know the desired carrier frequency
in order to do its 'smart' SNR signal processing and calculation.
When you off-tune, the chip no longer 'sees' the carrier where
you told it to 'look'. Under this condition, the processor
considers the SNR calculation to be invalid and returns a 0 dB
result.

By the way, this is part of the issue dxer's have with soft-mute.
The soft-mute calculation is based on the measured SNR. So when
you off-tune, the SNR goes to zero and soft-mute (if enabled)
kicks in.

Cheers,
Scott


--- In ultralightdx@..., Tony Germanotta <germanotta.tony@...> wrote:

Thanks Jim and Scott for the info. This is fascinating stuff for a non-techie like me. I have a question, though. When I offtune my PL-310 to one side or another of a frequency, not only does the signal strength drop a few notches on the volume knob, I always get a 0 SNR reading, no matter how well the station is coming through, no matter how tight the bandwidth. Does the radio somehow know the center of the signal I am shooting for? Of course, it really doesn't matter, the important thing is intelligibility. But it has me wondering just how smart this chip really is. Is it reading my mind, or just my WRTV Handbook?

On Jan 26, 2010, at 11:17 PM, sdwillingham wrote:


Jim gives an excellent explanation of the RSSI and SNR indicators.
Here are some further comments for more technical readers.

1) The abbreviation RSSI stands for "Received Signal Strength
Indicator", not "Relative . . ." Jim correctly emphasizes
that this strength refers to the LNA input voltage, not
electromagnetic field strength.

2) The signal-to-noise ratio Jim describes refers to signal strength
compared to the noise generated by the radio circuitry. The SNR
metric from the Si4734 is more sophisticated than that. If one
substitutes a short-circuit across the AM antenna terminals, he
will see the RSSI drop to 2-5 dBuV. With an antenna connected
and "between stations", the RSSI can be 30 or more dBuV. Yet the
Si4734 does not report the SNR as 25 dB, i.e. the signal strength
above the receiver noise floor. Instead, the chip reports a
metric measuring the signal strength relative to atmospheric
noise and interference. Of course, if the atmospheric noise is
low enough (or antenna gain is inadaquate), the SNR calculation
will reflect the receiver circuit's noise floor. I wish I
could give more detail about the calculation, but I believe that
is proprietary information.

Cheers,
Scott


Re: [IRCA] Here's an interesting sidebar to the Haiti Disaster

Russ Edmunds <wb2bjh@...>
 

1030 on AM


Russ Edmunds
Blue Bell, PA ( 360' ASL )
[15 mi NNW of Philadelphia]
40:08:45N; 75:16:04W, Grid FN20id
<wb2bjh@...>
FM: Yamaha T-80 & Onkyo T-450RDS w/ APS9B @15'
AM: Modified Sony ICF 2010 barefoot

--- On Wed, 1/27/10, John H. Bryant <bjohnorcas@...> wrote:

From: John H. Bryant <bjohnorcas@...>
Subject: Re: [IRCA] Here's an interesting sidebar to the Haiti Disaster
To: rtetro@..., "Mailing list for the International Radio Club of America" <irca@...>
Date: Wednesday, January 27, 2010, 11:16 AM
Some of us should be able to hear
this, even with ultralights...
Commando Solo is an AM band signal, likely on the lower
band and,
unlike the local Haitian stations, the equipment should be
operating
at 100% efficiency.  One of the best opportunities
ever to hear
Haiti. WHAT FREQUENCY???  This link gets to a CNN
story that does not
list the frequency.... the video clip... great to
see/listen... shows
several shots where the transmitted frequency is just off
camera... RATS.

Help from anyone??

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



At 10:39 AM 1/27/2010 -0500, you wrote:
From Tom Taylor's column on today's Radio-Info
newsletter





Haiti's newest radio station is broadcasting from the
skies.

Thanks to a specially-equipped U.S. Air Force C-130
that's flying
very slowly above the Caribbean country, broadcasting
an AM signal
in Creole. The programming is mostly Voice of America,
though CNN
<http://radio-info.us1.list-manage.com/track/click?u=16f606482a795f
a597872a8f1&id=5dec445cae&e=491e0cea53> 
says there are also
announcements from Haitian officials about the latest
on the
earthquake emergency. The AM antenna is a 264-foot
"long wire"
that's "dangling from [the plane's] belly like a plumb
line." It's
kept vertical by a 500-pound lead weight - not exactly
your usual
antenna setup on the ground. The plane also has four FM
antennas,
mounted on the wings and fuselage of the workhorse
aircraft. They
call the plane "Commando Solo" - and the CNN report is
a great
reminder of radio's role during emergencies. Just to
make sure the
target audience can hear the Commando Solo, the
Department of
Defense has distributed thousands of solar and hand-
crank-operated
radios.



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Opinions expressed in messages on this mailing list are
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To Post a message: irca@...


Re: Commando Solo Broadcasting on AM to Haiti

Tony Germanotta
 

According to this site, it's on 92.4, 104.1 and AM 1030. http://mt-shortwave.blogspot.com/2010/01/us-military-delivers-self-powered.html

Also Kim Elliot has this story on his site that talks about the mission and quotes the former site and DOD for those frequencies. http://kimelli.nfshost.com/index.php?id=8200.  Both of the sites claim copywrite, so I won't cut and paste. Hope this helps. 

In addition to Boston's powerhouse on that frequency, there seems to be a station in Orlando, so it might be difficult to grab. But that's what makes it so much fun.




On Jan 27, 2010, at 11:15 AM, John H. Bryant wrote:

 

>From Tom Taylor's column on today's Radio-Info newsletter

Haiti's newest radio station is broadcasting from the skies.

Thanks to a specially-equipped U.S. Air Force C-130 that's flying
very slowly above the Caribbean country, broadcasting an AM signal
in Creole. The programming is mostly Voice of America, though CNN
< http://radio-info.us1.list-manage.com/track/click?u=16f606482a795f
a597872a8f1&id=5dec445cae&e=491e0cea53> says there are also
announcements from Haitian officials about the latest on the
earthquake emergency. The AM antenna is a 264-foot "long wire"
that's "dangling from [the plane's] belly like a plumb line." It's
kept vertical by a 500-pound lead weight - not exactly your usual
antenna setup on the ground. The plane also has four FM antennas,
mounted on the wings and fuselage of the workhorse aircraft. They
call the plane "Commando Solo" - and the CNN report is a great
reminder of radio's role during emergencies. Just to make sure the
target audience can hear the Commando Solo, the Department of
Defense has distributed thousands of solar and hand- crank-operated
radios.

 
Some of us should be able to hear this, even with ultralights... It is an AM band signal, likely on the lower band and, unlike the local Haitian stations, the equipment should be operating at 100% efficiency.  One of the best opportunities ever to hear Haiti. WHAT FREQUENCY???  This link gets to a CNN story that does not list the frequency.... the video clip... great to see/listen... shows several shots where the transmitted frequency is just off camera... RATS.

Help from anyone??

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



Re: Commando Solo Broadcasting on AM to Haiti

Deane McIntyre <Deane@...>
 

*This message was transferred with a trial version of CommuniGate(tm) Pro*

On 27-Jan-10, at 9:15 AM, John H. Bryant wrote:


Some of us should be able to hear this, even with ultralights... It is an AM band signal, likely on the lower band and, unlike the local Haitian stations, the equipment should be operating at 100% efficiency. One of the best opportunities ever to hear Haiti. WHAT FREQUENCY??? This link gets to a CNN story that does not list the frequency.... the video clip... great to see/listen... shows several shots where the transmitted frequency is just off camera... RATS.

Help from anyone??
1030 kHz.

73,

Deane McIntyre
VE6BPO


latest logs

Allen Willie
 

 
 
Hi Guys,
 
Decent conditions last night and early this morning  in the North Atlantic with these logs and  1 new one
 
850 khz - WFTL - West Palm Beach, Florida  1/27/10  9:50 UTC w/ news and talk, mentions of Florida
 
1035 khz - R. Clube  Belmonte, Portugal  1/26/10  22:47 UTC  w/ portugeuse talk and music
 
1160 khz - WYLL - Chicago, Illinois  1/26/10  5:12 UTC  w/ religious programming and legal ID
 
 670 khz - WSCR - Chicago, Illinois  1/27/10  3:49 UTC w/ Basketball game, "You're listening to Basketball on the Score "
 
1570 khz - XERF - Ciudad Acuna ,Mexico   1/27/10  9:40 UTC   w/ spanish talk and music , mention of  La  Poderosa
 
1380 khz - WTJK - South Beloit, Illinois   1/27/10  4:20 UTC  w/ sports talk , ESPN Radio 1380 ID , ESPN ID's ( mixing with CKPC Brantford,Ontario)  *** NEW ***
 
 
73
 
Allen Willie
St. John's, Newfoundland
SRF-M37V barefoot
 
 
 


Looking for the perfect gift? Give the gift of Flickr!


Commando Solo Broadcasting on AM to Haiti

John H. Bryant <bjohnorcas@...>
 

>From Tom Taylor's column on today's Radio-Info newsletter

Haiti's newest radio station is broadcasting from the skies.

Thanks to a specially-equipped U.S. Air Force C-130 that's flying
very slowly above the Caribbean country, broadcasting an AM signal
in Creole. The programming is mostly Voice of America, though CNN
< http://radio-info.us1.list-manage.com/track/click?u=16f606482a795f
a597872a8f1&id=5dec445cae&e=491e0cea53> says there are also
announcements from Haitian officials about the latest on the
earthquake emergency. The AM antenna is a 264-foot "long wire"
that's "dangling from [the plane's] belly like a plumb line." It's
kept vertical by a 500-pound lead weight - not exactly your usual
antenna setup on the ground. The plane also has four FM antennas,
mounted on the wings and fuselage of the workhorse aircraft. They
call the plane "Commando Solo" - and the CNN report is a great
reminder of radio's role during emergencies. Just to make sure the
target audience can hear the Commando Solo, the Department of
Defense has distributed thousands of solar and hand- crank-operated
radios.

 
Some of us should be able to hear this, even with ultralights... It is an AM band signal, likely on the lower band and, unlike the local Haitian stations, the equipment should be operating at 100% efficiency.  One of the best opportunities ever to hear Haiti. WHAT FREQUENCY???  This link gets to a CNN story that does not list the frequency.... the video clip... great to see/listen... shows several shots where the transmitted frequency is just off camera... RATS.

Help from anyone??

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


Re: G8 signal strength meter

Tony Germanotta
 

Thanks Jim and Scott for the info. This is fascinating stuff for a non-techie like me.  I have a question, though. When I offtune my PL-310 to one side or another of a frequency, not only does the  signal strength drop a few notches on the volume knob,  I always get a 0 SNR reading, no matter how well the station is coming through, no matter how tight the bandwidth. Does the radio somehow know the center of the signal I am shooting for? Of course, it really doesn't matter, the important thing is intelligibility. But it has me wondering just how smart this chip really is.  Is it reading my mind, or just my WRTV Handbook?
 

On Jan 26, 2010, at 11:17 PM, sdwillingham wrote:

 


Jim gives an excellent explanation of the RSSI and SNR indicators.
Here are some further comments for more technical readers.

1) The abbreviation RSSI stands for "Received Signal Strength
Indicator", not "Relative . . ." Jim correctly emphasizes
that this strength refers to the LNA input voltage, not
electromagnetic field strength.

2) The signal-to-noise ratio Jim describes refers to signal strength
compared to the noise generated by the radio circuitry. The SNR
metric from the Si4734 is more sophisticated than that. If one
substitutes a short-circuit across the AM antenna terminals, he
will see the RSSI drop to 2-5 dBuV. With an antenna connected
and "between stations", the RSSI can be 30 or more dBuV. Yet the
Si4734 does not report the SNR as 25 dB, i.e. the signal strength
above the receiver noise floor. Instead, the chip reports a
metric measuring the signal strength relative to atmospheric
noise and interference. Of course, if the atmospheric noise is
low enough (or antenna gain is inadaquate), the SNR calculation
will reflect the receiver circuit's noise floor. I wish I
could give more detail about the calculation, but I believe that
is proprietary information.

Cheers,
Scott



Re: Damaged my Si4734

sdwillingham
 

Sorry to hear that Roy. I guess it might be a smart precaution to
short AMI to ground while soldering the antenna in.

Shoot me an email with your shipping address. I'm sure I can find
a replacement part around the lab here.

I don't think that a C40 part is likely to work in the G8/PL-3XX
radios until Tecsun ships it. (And I have no clue if, or when that
might be.) From playing with my PL-300, I believe it is using
a firmware 'patch'. So, although the C40 firmware should be
backwards compatible, the radio (which expects a B20) will try to
download patch code during the power-up process. Unfortunately,
patch code is specific to the exact firmware revision, so the
likely result is program corruption and CRC errors.

-Scott-

--- In ultralightdx@..., "Roy" <roy.dyball@...> wrote:


Hi All

It had to happen after many multiple operations and hundreds of hours of
software development with my old faithful G8 I have damaged my Si4734
chip. I was sure that this was going to happen in the dozens of times I
made connections to the control lines. But no, a careless slip of a
Loopstick wire brought me undone.

I was unsoldering one of the loopstick wires when the heat travelled so
quickly up the 660 strand Litz wire that it burnt my finger. 660 Litz is
really flexible and with a nice tinned end it is relatively heavy. It
seemed to fall across the circuit board snapping and popping till it
came to rest. A coil made from 660 Litz is very low resistance.

Smoke was coming from the SW switching FET. Luckily I have one of these
and it was easy to replace. However the radio was deaf on AM with only a
bit of noise right at the bottom of the band, FM worked fine. To make
double sure I disconnected the switching diode thus eliminating the SW
pre amp this did not help. I also checked the AC coupling capacitor

Connecting the radio to my software showed that on every station that
the varactor was showing max count and capacitance (6143) so it is not
tuning. I have a really small propane torch so it only took 30 seconds
to remove the chip from the circuit board ready for the new one.

I figure this is a blessing in disguise as I really want to try out the
Ver40 firmware. The trouble is that those suppliers who stock the chip
only have Ver20 and with the stock numbers they have I don't think
they will be stocking Ver40 for a while. Has anybody in the group seen a
Si4734-C40 in their browsing for sale? I tried Mouser.com but they only
have the V20. Their price is good for the V20, about $15.00 but they
want $39.00 to ship an item 3mm square that is probably so light you
cannot way it.

I cannot speak highly enough about the Si4734 chip; it is a sturdy well
protected little chip. This was my fault so be careful when working with
660 Litz wire. Also if ever you remove the Si4734 from the circuit board
go out of your way to put it some ware safe as I have already misplaced
the old one. I had it on my bench and when I looked for it, it was gone.
It cannot have gone far and should turn up.

Cheers Roy.


Tecsun PL-310 Memory

john445 <john445@...>
 

Good morning:

I programmed the GY frequencies into memory on s PL-310 recently received. Now it seems I am unable to get out of the memory entry mode. When I try to enter a new frequency in the keypad, the radio shows the memory number entry on the display. Rotating the tuning knob only goes through the stored memories. I must be missing something very simple.....

Thanks,

John Mosman
WPE9GIZ
Madison, WI

P.S. Forgot to congratulate the new award winners yesterday...CONGRATS!

The new awards background pics are the greatest.


Re: Damaged my Si4734

jim_kr1s <jkearman@...>
 



--- In ultralightdx@..., "Roy" wrote:
>
>
>
> It had to happen after many multiple operations and hundreds of hours of software development with my old faithful G8 I have damaged my Si4734 chip.

Oh, no! Could be the LNA I guess. Arrrrgggh. If I have the right Mouser p/n, 634-SI4734-B20-GM, they show 126 in stock. If you can't get a B40 and want a replacement B20, it's on me. I'm sure I can get it mailed to me from Mouser and then on its way Down Under for a whole lot less than they're charging! I order from them frequently, and parts get here pretty quickly.

73,

Jim, KR1S
http://qrp.kearman.com/ 




Traverse City Loggings All Times Eastern

Antonios Kekalos <akekalos@...>
 

1.27.10, 0623, AM 550, WKRC, Cincinnati, OH, 392mi/630km, "55 News Talk Station", Optimus 12-174
1.27.10, 0630, AM 700, WLW, Cincinnati, OH, 392mi/630km, "News Radio 700 WLW", Optimus 12-174
1.27.10, 0633, AM 740, CFZM, Toronto, 318mi/512km, "AM 740 time 0635", Optimus 12-174
1.27.10, 0650, AM 860, ?CJBC?, Toronto, 318mi/512km, male & female French speakers, Optimus 12-174



--
Tony Kekalos
Traverse City, MI
SWLR-RN072
EN74es



Re: PL-380 Version 2?

Roy <roy.dyball@...>
 

Hi and Welcome to the group good to see another Aussie.

I have one of the first ones but I had not noticed that information on the flap. My one says 2009.9 VER 1. Thanks for pointing it out.

Roy.

--- In ultralightdx@..., J P wrote:
>
>
>
> Hello From Australia,
>
> First post to the group! I've just added a PL380 to the collection. I also have a PL-300WT. Both receivers are excellent. With regard to the post about a possible new model of the PL380 I notice that the end cardboard flap that the RX came in has the following printed on it - '2009.9 Ver.2'
>
> Anyone else got this?
>
>
> Jim
>
> _________________________________________________________________
> Time for a new car? Sell your old one fast!
> http://clk.atdmt.com/NMN/go/157637060/direct/01/
>


Damaged my Si4734

Roy <roy.dyball@...>
 

Hi All

It had to happen after many multiple operations and hundreds of hours of software development with my old faithful G8 I have damaged my Si4734 chip. I was sure that this was going to happen in the dozens of times I made connections to the control lines. But no, a careless slip of a Loopstick wire brought me undone.

I was unsoldering one of the loopstick wires when the heat travelled so quickly up the 660 strand Litz wire that it burnt my finger. 660 Litz is really flexible and with a nice tinned end it is relatively heavy. It seemed to fall across the circuit board snapping and popping till it came to rest. A coil made from 660 Litz is very low resistance.

Smoke was coming from the SW switching FET. Luckily I have one of these and it was easy to replace. However the radio was deaf on AM with only a bit of noise right at the bottom of the band, FM worked fine. To make double sure I disconnected the switching diode thus eliminating the SW pre amp this did not help. I also checked the AC coupling capacitor

Connecting the radio to my software showed that on every station that the varactor was showing max count and capacitance (6143) so it is not tuning. I have a really small propane torch so it only took 30 seconds to remove the chip from the circuit board ready for the new one.

I figure this is a blessing in disguise as I really want to try out the Ver40 firmware. The trouble is that those suppliers who stock the chip only have Ver20 and with the stock numbers they have I don't think they will be stocking Ver40 for a while. Has anybody in the group seen a Si4734-C40 in their browsing for sale? I tried Mouser.com but they only have the V20. Their price is good for the V20, about $15.00 but they want $39.00 to ship an item 3mm square that is probably so light you cannot way it.

I cannot speak highly enough about the Si4734 chip; it is a sturdy well protected little chip. This was my fault so be careful when working with 660 Litz wire. Also if ever you remove the Si4734 from the circuit board go out of your way to put it some ware safe as I have already misplaced the old one. I had it on my bench and when I looked for it, it was gone. It cannot have gone far and should turn up.

Cheers Roy.

 


PL-380 Version 2?

J P <deafasabeetle@...>
 


Hello From Australia,

First post to the group!  I've just added a PL380 to the collection.  I also have a PL-300WT.  Both receivers are excellent.  With regard to the post about a possible new model of the PL380 I notice that the end cardboard flap that the RX came in has the following printed on it - '2009.9 Ver.2'

Anyone else got this?


Jim



Sell your old one fast! Time for a new car?


Re: G8 signal strength meter

sdwillingham
 

Jim gives an excellent explanation of the RSSI and SNR indicators.
Here are some further comments for more technical readers.

1) The abbreviation RSSI stands for "Received Signal Strength
Indicator", not "Relative . . ." Jim correctly emphasizes
that this strength refers to the LNA input voltage, not
electromagnetic field strength.

2) The signal-to-noise ratio Jim describes refers to signal strength
compared to the noise generated by the radio circuitry. The SNR
metric from the Si4734 is more sophisticated than that. If one
substitutes a short-circuit across the AM antenna terminals, he
will see the RSSI drop to 2-5 dBuV. With an antenna connected
and "between stations", the RSSI can be 30 or more dBuV. Yet the
Si4734 does not report the SNR as 25 dB, i.e. the signal strength
above the receiver noise floor. Instead, the chip reports a
metric measuring the signal strength relative to atmospheric
noise and interference. Of course, if the atmospheric noise is
low enough (or antenna gain is inadaquate), the SNR calculation
will reflect the receiver circuit's noise floor. I wish I
could give more detail about the calculation, but I believe that
is proprietary information.

Cheers,
Scott