[Hackrf-dev] Rf amplifier not working

[giuseppe]

[Michael Ossmann]

activating rf amp silences the reception and does not increase tx level.
Is it PA broken alone or should I replace RF switch ic(s) as well?

Usually this can be repaired by replacing just the amplifier IC (U13 for RX or
U25 for TX).

Which is the expected behavior on RX if rf amp is engaged?

You should be able to observe an increase in signal power when the RF amp is
activated. If the RF amp is broken, activating the amp typically results in a
decrease in signal power instead of an increase.

By the way, your mail client has done an unneighborly thing in designating your
email as multipart/alternative with an empty text/plain section. In some mail
clients (and probably the mailing list digest) this makes the body of your
message appear empty.

Mike

[Mitja kocjančič]

I used this tutorial to repair it (pay someone to do it for me because I
don't know how to solder): http://www.t4f.org/articles/repairing-the-hackrf/
when I broke mein
not sure how I did it
and would like to know if there are any percussions I have to take so it
won't happen again

Post by Michael Ossmann

activating rf amp silences the reception and does not increase tx level.
Is it PA broken alone or should I replace RF switch ic(s) as well?

Usually this can be repaired by replacing just the amplifier IC (U13 for RX or
U25 for TX).

Which is the expected behavior on RX if rf amp is engaged?

You should be able to observe an increase in signal power when the RF amp is
activated. If the RF amp is broken, activating the amp typically results in a
decrease in signal power instead of an increase.
By the way, your mail client has done an unneighborly thing in designating your
email as multipart/alternative with an empty text/plain section. In some mail
clients (and probably the mailing list digest) this makes the body of your
message appear empty.
Mike
_______________________________________________
HackRF-dev mailing list
https://pairlist9.pair.net/mailman/listinfo/hackrf-dev

[Giuseppe Marullo]

Hello Mitja and Michael,

I knew the link, but my problem is that at the moment I could only use
Windows (*long* story, I selected a AMD R9 280 to play with
ESX/DirectPath I/O and linux support for AMD R9 sux), so my option to
understand the problem is tied to use SDR Console by sdr Radio and SDR
Angel. I don't know how to "map" rf amp to rx/tx gadgets on the gui.

On SDR Console 2.3 (used for Rx only), I have the following controls:

LNA (0-40dB, defaults to 24dB)
VGA (0-62 dB defaults to 20dB)
Ext Amp (off/On defaults to Off)

Listening to FM broadcast radios, it works if I keep Ext Amp off (it
should be used only in TX, right?). Changing LNA and/or VGA
increase/decrease the received signal and this is fine. Which is the
supposed behavior when I switch Ext Amp on during RECEPTION? Is it okay
that received signal weakens almost to vanish?

I ask this because I would expect no impact since the PA should not be
activated on reception, or am I wrong?

On SDR Angel(used for RX AND TX), same controls and same result on Rx.

When I try to transmit I have a signal, but if I engage the ext amp
almost nothing comes out. I use a dualband/DMR handheld almost one meter
near the HackRF antenna.

I am asking because I would like to know if I need to change just the PA
or also the rf switch are involved. I would order a couple of them (two
amps and two switches) but it seems that the switches are way nastier
than the amplifiers to solder so I would know for sure if the behavior
is related to just the PA being broken or worse.

I fried mine probably using a 1.2m 5/8 mobile antenna too near to the
DMR handheld to receive DMR transmissions.

Post by Michael Ossmann
By the way, your mail client has done an unneighborly thing in

designating your

Post by Michael Ossmann
email as multipart/alternative with an empty text/plain section. In

some mail

Post by Michael Ossmann
clients (and probably the mailing list digest) this makes the body of your
message appear empty

Interesting reading: https://stackoverflow.com/questions/8320141/multipart-alternative-subtype-when-client-use-it

Usually I send out messages using Automatic format and my email client is Thunderbird. This is the first time I get problems using it. If you don't mind could I send to you a couple of test messages, one encoded in text only and the other in auto to see what you do receive.
BTW, which email client are you using?
I am not a fan of HTML messages, I do rather prefer old plain text, and my impression was that it was what I was going to send using Auto on a new (blank message), more than willing to keep text only as default(and not a double whatever format), thank you.

Giuseppe Marullo

IW2JWW - JN45RQ

ps: this answer is plain text only, hopefully it will be okay

[Mitja kocjančič]

You probably broke your PA (for some reason if PA isbroken it weakens the
signal instead of making it stronger)

Just to be sure replace both PAs (recieve and transmitt one) if rfswitch
would be broken probably nothing would happen if you activated your PA



via Newton Mail
[https://cloudmagic.com/k/d/mailapp?ct=pa&cv=9.3.59&pv=4.4.2&source=email_footer_2]
On Sun, Feb 11, 2018 at 2:00pm, Giuseppe Marullo < ***@marullo.it
[***@marullo.it] > wrote:
Hello Mitja and Michael,

I knew the link, but my problem is that at the moment I could only use
Windows (*long* story, I selected a AMD R9 280 to play with
ESX/DirectPath I/O and linux support for AMD R9 sux), so my option to
understand the problem is tied to use SDR Console by sdr Radio and SDR
Angel. I don't know how to "map" rf amp to rx/tx gadgets on the gui.

On SDR Console 2.3 (used for Rx only), I have the following controls:

LNA (0-40dB, defaults to 24dB)
VGA (0-62 dB defaults to 20dB)
Ext Amp (off/On defaults to Off)

Listening to FM broadcast radios, it works if I keep Ext Amp off (it
should be used only in TX, right?). Changing LNA and/or VGA
increase/decrease the received signal and this is fine. Which is the
supposed behavior when I switch Ext Amp on during RECEPTION? Is it okay
that received signal weakens almost to vanish?

I ask this because I would expect no impact since the PA should not be
activated on reception, or am I wrong?

On SDR Angel(used for RX AND TX), same controls and same result on Rx.

When I try to transmit I have a signal, but if I engage the ext amp
almost nothing comes out. I use a dualband/DMR handheld almost one meter
near the HackRF antenna.

I am asking because I would like to know if I need to change just the PA
or also the rf switch are involved. I would order a couple of them (two
amps and two switches) but it seems that the switches are way nastier
than the amplifiers to solder so I would know for sure if the behavior
is related to just the PA being broken or worse.

I fried mine probably using a 1.2m 5/8 mobile antenna too near to the
DMR handheld to receive DMR transmissions.

Post by Michael Ossmann
By the way, your mail client has done an unneighborly thing in

designating your

Post by Michael Ossmann
email as multipart/alternative with an empty text/plain section. In

some mail

Post by Michael Ossmann
clients (and probably the mailing list digest) this makes the body of your
message appear empty

Interesting reading:
https://stackoverflow.com/questions/8320141/multipart-alternative-subtype-when-client-use-it

Usually I send out messages using Automatic format and my email client is
Thunderbird. This is the first time I get problems using it. If you don't
mind could I send to you a couple of test messages, one encoded in text
only and the other in auto to see what you do receive.
BTW, which email client are you using?
I am not a fan of HTML messages, I do rather prefer old plain text, and my
impression was that it was what I was going to send using Auto on a new
(blank message), more than willing to keep text only as default(and not a
double whatever format), thank you.

Giuseppe Marullo

IW2JWW - JN45RQ

ps: this answer is plain text only, hopefully it will be okay