TVRX Microtune 4702 (4937) Gain question

GNU Radio
1

Hi All,

I can not see in source code where GR is setting the TVRXx gain. I’m
referring to
gnuradio-core/src/lib/io/microtune.cc

If so (not set), what does it default to, max? See page 12 and forward.
The tuner document can be found at
http://www.poes-weather.com/~patrik/usrp/4937-DI5-3x8899-2.pdf

Patrik

2

On Fri, Jun 24, 2011 at 5:45 PM, Patrik T.
[email protected]wrote:

**
Hi All,

I can not see in source code where GR is setting the TVRXx gain. I’m
referring to
gnuradio-core/src/lib/io/microtune.cc

I’m don’t think that code is related to TVRX. For old non-uhd driver you
need to look in the usrp/host/lib/ directory.

If so (not set), what does it default to, max? See page 12 and forward. The
tuner document can be found at
http://www.poes-weather.com/~patrik/usrp/4937-DI5-3x8899-2.pdf

In db_tv_rx.cc constructor, line 101, the gain is initialized to middle.
The gain ranges are also available via the API and you can see many of
the
examples also initialize the gain to middle value.

Alex

3

On 24/06/2011 11:45 AM, Patrik T. wrote:

Hi All,
I can not see in source code where GR is setting the TVRXx gain. I’m
referring to
gnuradio-core/src/lib/io/microtune.cc
If so (not set), what does it default to, max? See page 12 and
forward. The tuner document can be found at
Loading...
http://www.poes-weather.com/~patrik/usrp/4937-DI5-3x8899-2.pdf
Patrik

I don’t know where that file came from–it’s not in the current Gnu
Radio source tree.

But certainly, in UHD, in the “db_tvrx.cpp” file the constructor for the
“tvrx” class initializes the gains on the device.

4

Aha I see,

It seems to be time for me to “upgrade” to uhd from traditional

Many thanks,
Patrik
----- Original Message -----
From: Alexandru C.
To: Patrik T.
Cc: [email protected]
Sent: Friday, June 24, 2011 19:14
Subject: Re: [Discuss-gnuradio] TVRX Microtune 4702 (4937) Gain
question

On Fri, Jun 24, 2011 at 5:45 PM, Patrik T. [email protected]
wrote:

Hi All,

I can not see in source code where GR is setting the TVRXx gain. I'm

referring to
gnuradio-core/src/lib/io/microtune.cc

I’m don’t think that code is related to TVRX. For old non-uhd driver
you need to look in the usrp/host/lib/ directory.

If so (not set), what does it default to, max? See page 12 and

forward. The tuner document can be found at
Loading...

In db_tv_rx.cc constructor, line 101, the gain is initialized to
middle.
The gain ranges are also available via the API and you can see many of
the examples also initialize the gain to middle value.

Alex

5

It came from a VERY old traditional GR build.
I thought no changes there in source code init stage was altered after
moving on to uhd, I was wrong.

Time for me to upgrade from trad to uhd. Latest git trad compile does
serve my needs still 100%

Thanks,
Patrik
----- Original Message -----
From: Marcus D. Leech
To: [email protected]
Sent: Friday, June 24, 2011 19:11
Subject: Re: [Discuss-gnuradio] TVRX Microtune 4702 (4937) Gain
question

On 24/06/2011 11:45 AM, Patrik T. wrote:
Hi All,

I can not see in source code where GR is setting the TVRXx gain. I'm

referring to
gnuradio-core/src/lib/io/microtune.cc

If so (not set), what does it default to, max? See page 12 and

forward. The tuner document can be found at
Loading...

Patrik

I don’t know where that file came from–it’s not in the current Gnu
Radio source tree.

But certainly, in UHD, in the “db_tvrx.cpp” file the constructor for
the “tvrx” class initializes the gains on the device.

6

Just to clarify,

I am not talking about setting the gain in software, spectrum plot gain
for example.
I’m talking about the hardware gain setting controlled via I2C

Patrik
----- Original Message -----
From: Alexandru C.
To: Patrik T.
Cc: [email protected]
Sent: Friday, June 24, 2011 19:14
Subject: Re: [Discuss-gnuradio] TVRX Microtune 4702 (4937) Gain
question

On Fri, Jun 24, 2011 at 5:45 PM, Patrik T. [email protected]
wrote:

Hi All,

I can not see in source code where GR is setting the TVRXx gain. I'm

referring to
gnuradio-core/src/lib/io/microtune.cc

I’m don’t think that code is related to TVRX. For old non-uhd driver
you need to look in the usrp/host/lib/ directory.

If so (not set), what does it default to, max? See page 12 and

forward. The tuner document can be found at
http://www.poes-weather.com/~patrik/usrp/4937-DI5-3x8899-2.pdf

In db_tv_rx.cc constructor, line 101, the gain is initialized to
middle.
The gain ranges are also available via the API and you can see many of
the examples also initialize the gain to middle value.

Alex

7

On 24/06/2011 1:06 PM, Patrik T. wrote:

It came from a VERY old traditional GR build.
I thought no changes there in source code init stage was altered
after moving on to uhd, I was wrong.
Time for me to upgrade from trad to uhd. Latest git trad compile
does serve my needs still 100%
Thanks,

The UHD interface is very different than traditional. But if you use
Python (or better, GRC), you should have very little pain in
doing the upgrade.