I see. Is there someone we can contact at Ettus for this?
Khalid
On 01/16/2015 03:06 PM, khalid.el-darymli wrote:
I see. Is there someone we can contact at Ettus for this?
Khalid
Send a note to [email protected]
If the card is within waranty period, you’ll likely get a replacement.
Otherwise, the NI repair policy kicks in, and it wouldn’t be worth
getting it
repaired.
We are using almost the same IC in our product, as a driver for a
transmitting coil in industrial environment, for material test, and we
had never ever fail one of those. Must be around 4k or 5k of those ICs
we have out in the field, and the only failures were two or three that
came dead from the PCB manufacturer. Even a hard short never was able to
kill one.
Ralph.
From: discuss-gnuradio-bounces+ralph=removed_email_address@domain.invalid
[mailto:discuss-gnuradio-bounces+ralph=removed_email_address@domain.invalid] On Behalf Of
Marcus D. Leech
Sent: Friday, January 16, 2015 8:12 PM
To: khalid.el-darymli; Michael R.
Cc: [email protected]
Subject: Re: [Discuss-gnuradio] Max Output Power from the LFTX
On 01/16/2015 02:08 PM, khalid.el-darymli wrote:
Hi All,
Just to update you in case somebody else comes across this problem.
Following Mike’s advice, we replaced the LFTX daughterboard with a new
one. We’re getting now 1 V p-p. This is around 4 dBm.
Thanks very much for your help.
Best regards,
Khalid
Interesting. The driver chip that’s used, as a unity-gain
differential-to-single-ended driver, is, according to the datasheets,
pretty robust. So, it would
be interesting to know exactly what the failure mode is.
On Tue, Jan 6, 2015 at 2:38 PM, Michael R. <[email protected]
mailto:[email protected] > wrote:
Hi Khalid,
I had a similar issue with an LFTX that I had been working with for
about two years. I actually had two boards running on separate USRP2’s
and both were working fine for quite a while, but I recently noticed
that one had a drastically lower output range. I ended up replacing the
LFTX and all is working well now, so I’m assuming it was a hardware
issue that came up at some point.
I didn’t take the time to look for the problem, but I figured I’d share
this info since what you’re seeing might be a hardware issue rather than
something you can resolve with settings.
-Mike
On Tue, Jan 6, 2015 at 12:59 PM, khalid.el-darymli
<[email protected] mailto:[email protected] > wrote:
Output power is determined largely by baseband signal magnitude in that case.
Yes, I understand. And I noticed that for baseband signal with an
amplitude > 1, the pass-band signal gets clipped off. So I assume that
an amplitude of 1 for the baseband signal should deliver the maximum
output power (for the pass-band signal).
My question was, what is the maximum power one can get for the pass-band
signal output from LFTX? In your earlier reply, you said it is around
+7dBm, am I getting this right? In my case, for a baseband amplitude of
around 1, I am only getting -28.13dBm, much less than what you said, I
am not sure, why?
Thanks,
Khalid
On Tue, Jan 6, 2015 at 1:56 PM, Marcus D. Leech <[email protected]
mailto:[email protected] > wrote:
Thanks Marcus for your reply.
Probably somewhere in the neighborhood of +7dBm, maybe a little more.
The LF/BASIC series have no gain in either path, so you’re just looked
at buffered ADC ouput.
So, ~ +7dBm is the max output power I supposed to get from the LFTX
daughterboard? How do I get that?
Since I am only getting -28.13 dBm, does that mean I have some issue
with my LFTX daughterboard?
Khalid
Output power is determined largely by baseband signal magnitude in that
case.
Message: 2
Date: Tue, 6 Jan 2015 10:13:45 -0330
From: “khalid.el-darymli” <[email protected]
mailto:[email protected] >
To: "[email protected] mailto:[email protected] "
<[email protected] mailto:[email protected] >
Subject: [Discuss-gnuradio] Max Output Power from the LFTX
daughterboard
Message-ID:
<CACdmG=zCHATiwrtv=wBVLwG0_
[email protected]
mailto:[email protected] >
Content-Type: text/plain; charset=“utf-8”
Hi,
What is the maximum output power from the LFTX daughterboard when used
with
the USRP N200?
According to this datasheet [1], the N200 with the WBX daughterbaord
provide an output power of 15 dBm. However, when using the LFTX
daughterboard, I am getting a much less output power.
[1]
http://www.ettus.com/content/files/07495_Ettus_N200-210_DS_Flyer_HR.pdf
In GNU Radio with the USRP N200, we use a sinusoid with a frequency of
150
kHz and an amplitude of 0.98, fed into the LFTX daughterboard for a
center
frequency of 5 MHz. When the output of LFTX is plugged into a scope
terminated with a 50-ohm terminator, the scope reads 24.8 mV
(peak-to-peak). This is around -28.13 dBm.
Is this the max power one can get out of the LFTX daughterboard?
Thanks.
Best regards,
Khalid
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Message: 3
Date: Tue, 06 Jan 2015 08:48:08 -0500
From: “Marcus D. Leech” <[email protected] mailto:[email protected] >
To: [email protected] mailto:[email protected]
Subject: Re: [Discuss-gnuradio] Max Output Power from the LFTX
daughterboard
Message-ID: <[email protected]
mailto:[email protected] >
Content-Type: text/plain; charset=UTF-8; format=flowed
On 01/06/2015 08:43 AM, khalid.el-darymli wrote:
Best regards,
Khalid
Probably somewhere in the neighborhood of +7dBm, maybe a little more.
The LF/BASIC series have no gain in either path, so you’re just looked
at buffered ADC ouput.
–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
Usually you just see, the IC is defective, that’s all, and this is what
we already know anyway 
Ralph.
From: discuss-gnuradio-bounces+ralph=removed_email_address@domain.invalid
[mailto:discuss-gnuradio-bounces+ralph=removed_email_address@domain.invalid] On Behalf Of
Marcus D. Leech
Sent: Friday, January 16, 2015 8:59 PM
To: khalid.el-darymli
Cc: [email protected]
Subject: Re: [Discuss-gnuradio] Max Output Power from the LFTX
On 01/16/2015 02:54 PM, khalid.el-darymli wrote:
I see. If you would like to diagnose the problem, we can ship you the
malfunctioned daughterboard?
Thanks,
Khalid
Thanks. I personally wouldn’t have time/equipment to really diagnose
it. So it would be up to Ettus R&D as to whether they want it back to
see
what the failure mode is.
I’ve been doing Ettus support for 6 years, and LF_TX are not generally
items that show up with RMA requests very often.
On Fri, Jan 16, 2015 at 4:17 PM, Marcus D. Leech <[email protected]
mailto:[email protected] > wrote:
On 01/16/2015 02:42 PM, khalid.el-darymli wrote:
We were using only one Tx channel with the Subdev Spec in the USRP Sink
is set to A:AB
Could the failure be due to that the other (idle) Tx channel is left
open circuit (i.e., not terminated by 50 ohms)?
That seems quite unlikely. These aren’t “precious princess” RF power
transistors, but reasonably-robust differential-to-unbalanced drivers.
I’d
be very surprised if they couldn’t handle an open-circuit condition.
Khalid
On Fri, Jan 16, 2015 at 3:41 PM, Marcus D. Leech <[email protected]
mailto:[email protected] > wrote:
On 01/16/2015 02:08 PM, khalid.el-darymli wrote:
Hi All,
Just to update you in case somebody else comes across this problem.
Following Mike’s advice, we replaced the LFTX daughterboard with a new
one. We’re getting now 1 V p-p. This is around 4 dBm.
Thanks very much for your help.
Best regards,
Khalid
Interesting. The driver chip that’s used, as a unity-gain
differential-to-single-ended driver, is, according to the datasheets,
pretty robust. So, it would
be interesting to know exactly what the failure mode is.
On Tue, Jan 6, 2015 at 2:38 PM, Michael R. <[email protected]
mailto:[email protected] > wrote:
Hi Khalid,
I had a similar issue with an LFTX that I had been working with for
about two years. I actually had two boards running on separate USRP2’s
and both were working fine for quite a while, but I recently noticed
that one had a drastically lower output range. I ended up replacing the
LFTX and all is working well now, so I’m assuming it was a hardware
issue that came up at some point.
I didn’t take the time to look for the problem, but I figured I’d share
this info since what you’re seeing might be a hardware issue rather than
something you can resolve with settings.
-Mike
On Tue, Jan 6, 2015 at 12:59 PM, khalid.el-darymli
<[email protected] mailto:[email protected] > wrote:
Output power is determined largely by baseband signal magnitude in that case.
Yes, I understand. And I noticed that for baseband signal with an
amplitude > 1, the pass-band signal gets clipped off. So I assume that
an amplitude of 1 for the baseband signal should deliver the maximum
output power (for the pass-band signal).
My question was, what is the maximum power one can get for the pass-band
signal output from LFTX? In your earlier reply, you said it is around
+7dBm, am I getting this right? In my case, for a baseband amplitude of
around 1, I am only getting -28.13dBm, much less than what you said, I
am not sure, why?
Thanks,
Khalid
On Tue, Jan 6, 2015 at 1:56 PM, Marcus D. Leech <[email protected]
mailto:[email protected] > wrote:
Thanks Marcus for your reply.
Probably somewhere in the neighborhood of +7dBm, maybe a little more.
The LF/BASIC series have no gain in either path, so you’re just looked
at buffered ADC ouput.
So, ~ +7dBm is the max output power I supposed to get from the LFTX
daughterboard? How do I get that?
Since I am only getting -28.13 dBm, does that mean I have some issue
with my LFTX daughterboard?
Khalid
Output power is determined largely by baseband signal magnitude in that
case.
Message: 2
Date: Tue, 6 Jan 2015 10:13:45 -0330
From: “khalid.el-darymli” <[email protected]
mailto:[email protected] >
To: "[email protected] mailto:[email protected] "
<[email protected] mailto:[email protected] >
Subject: [Discuss-gnuradio] Max Output Power from the LFTX
daughterboard
Message-ID:
<CACdmG=zCHATiwrtv=wBVLwG0_
[email protected]
mailto:[email protected] >
Content-Type: text/plain; charset=“utf-8”
Hi,
What is the maximum output power from the LFTX daughterboard when used
with
the USRP N200?
According to this datasheet [1], the N200 with the WBX daughterbaord
provide an output power of 15 dBm. However, when using the LFTX
daughterboard, I am getting a much less output power.
[1]
http://www.ettus.com/content/files/07495_Ettus_N200-210_DS_Flyer_HR.pdf
In GNU Radio with the USRP N200, we use a sinusoid with a frequency of
150
kHz and an amplitude of 0.98, fed into the LFTX daughterboard for a
center
frequency of 5 MHz. When the output of LFTX is plugged into a scope
terminated with a 50-ohm terminator, the scope reads 24.8 mV
(peak-to-peak). This is around -28.13 dBm.
Is this the max power one can get out of the LFTX daughterboard?
Thanks.
Best regards,
Khalid
-------------- next part --------------
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Message: 3
Date: Tue, 06 Jan 2015 08:48:08 -0500
From: “Marcus D. Leech” <[email protected] mailto:[email protected] >
To: [email protected] mailto:[email protected]
Subject: Re: [Discuss-gnuradio] Max Output Power from the LFTX
daughterboard
Message-ID: <[email protected]
mailto:[email protected] >
Content-Type: text/plain; charset=UTF-8; format=flowed
On 01/06/2015 08:43 AM, khalid.el-darymli wrote:
Best regards,
Khalid
Probably somewhere in the neighborhood of +7dBm, maybe a little more.
The LF/BASIC series have no gain in either path, so you’re just looked
at buffered ADC ouput.
–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
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