RX2 not same signal level as RX1

N4XD
Posts: 34
Joined: Tue Sep 29, 2020 11:59 pm

RX2 not same signal level as RX1

Postby N4XD » Wed Oct 21, 2020 1:57 am

Setup
Anan 7000dle Mk2
Thetis V 2.8.9 64 bit
Antenna: a receive array. For this test the receive antenna output is sent to both RX1 and RX2. RX1 uses ant 2 input (and is set up in the antenna page) and the antenna for RX2 is connected to the Anan RX2 jack on the back.

I've checked and double checked and everything is set up the same for both receivers. However, the signal levels are much, much lower on RX2 than the main receiver (RX1). Again, for this test (i.e. not how I will run things) both receivers are attached to the same receive antenna.

My goal: To use two different antennas, one to each receiver, to be able to listen in 2 different directions during contests. I use that set up during 160 contests.

I'm thinking I must have missed something obvious but its not obvious to me. I have verified that AGC levels set the same for both. No attenuation set for either receiver. Same mode and filter bandwidth.

Any help will be appreciated.

Thanks
Ron
N4XD
User avatar
w-u-2-o
Posts: 2910
Joined: Fri Mar 10, 2017 1:47 pm

Re: RX2 not same signal level as RX1

Postby w-u-2-o » Wed Oct 21, 2020 2:16 am

How are you splitting the antenna between the two inputs? Have you tried swapping the cables between ANT2 and RX2 to see if the problem follows the cables? Have you tried using a signal generator on each input in turn?
N4XD
Posts: 34
Joined: Tue Sep 29, 2020 11:59 pm

Re: RX2 not same signal level as RX1

Postby N4XD » Wed Oct 21, 2020 11:00 am

All good questions. I have swapped cables and no change. I.E. not a cable problem. I split the signal using a bnc T. Not ideal but for this, fine since its not a permanent set up. No, don't have a sig gen but there were a few very loud signals on the band so the difference was easy to see.

Wondering what is in the receive chain that might have blown up.

I do see the waterfall background change color when I change the rx2 attenuation which I think I'd expect.

My plan today is to add an external preamp to rx2 and see what that does. I'd obviously expect sigs to increase.

Would really like to see a schematic of the RX2 path.

Thanks

Ron
N4XD
Posts: 34
Joined: Tue Sep 29, 2020 11:59 pm

Re: RX2 not same signal level as RX1

Postby N4XD » Wed Oct 21, 2020 3:15 pm

I did find an old HP sig gen to use.

For the same level of receive signal (I arbitrarily chose S5) it took a -90dbm signal into ant 1 for rx1 to get the S5 receive signal. For RX2 it took -40dbm so obviously there is an issue somewhere with RX2.

Any help troubleshooting this will be greatly appreciated.

Another related question.Is RX2 the only input available for the 2nd ADC?


Thanks

Ron
User avatar
w-u-2-o
Posts: 2910
Joined: Fri Mar 10, 2017 1:47 pm

Re: RX2 not same signal level as RX1

Postby w-u-2-o » Wed Oct 21, 2020 3:22 pm

The circuitry and paths for ADC0 aka RX1, and ADC1 aka RX2, or nearly identical. The only difference is the ANT1/2/3 and PureSignal related switching relays on the RX1 path.

Apache is still prohibiting the public posting of the 7000 and 8000 schematics. However if you contact the factory directly they will provide them to you.

Other than the additional switching relays on RX1, the paths again are identical. On the PA/filter board:

Rear panel connector > grounding relay > limiter > RLP-40+ LPF > preselector filter bank > connector to the Orion MKII board

On the Orion MKII board

Orion MKII connector > limiter > DAT-31-SP+ step attenuator > RLP-50+ LPF > transformer > LTC6400-14 preamp > LTC2208CUP ADC

Adding a pre-amp to the RX2 input is a waste of time. If the signal levels are not nearly the same within a dB or two then something is broken.

To be maximally conservative, test this with Protocol 1 firmware installed.

eta yes, the only path to the second ADC is via the RX2 rear panel input. However, if you opened up your unit you could swap the cables on the Orion MKII RX1 and RX2 input connectors. If the problem moves with the swap, then you know the problem is between the rear panel and the Orion MKII. Alternately, you can attach the signal generator directly to the Orion MKII RX1 and RX2 input connectors.
N4XD
Posts: 34
Joined: Tue Sep 29, 2020 11:59 pm

Re: RX2 not same signal level as RX1

Postby N4XD » Wed Oct 21, 2020 11:09 pm

Thanks. That is very detailed and useful information.

I've requested the schematics, thanks for that tip.

Guess I'll have to dig into the radio a bit.

Will post an update when I have it.

Ron
kb3bf
Posts: 9
Joined: Mon Mar 02, 2020 7:15 pm
Location: columbia Md.

RX1 has permanently dropped some 20dB

Postby kb3bf » Sat Nov 28, 2020 3:29 am

Hello,
I believe my ANAN 7000 DLE has suffered permanent front-end damage. Very weak reception on RX1 about 20dB. Only the strongest signals can be barely heard in noise. I received the schematics and will try to trace the path, wondering if a relay of FET got damaged.
thanks for any advice/suggestions,

kb3bf Chris
Columbia Md.
User avatar
w-u-2-o
Posts: 2910
Joined: Fri Mar 10, 2017 1:47 pm

Re: RX2 not same signal level as RX1

Postby w-u-2-o » Sat Nov 28, 2020 12:15 pm

Chris: there's a dozen things that could be wrong. Does RX2 work ok? What happens when you connect an antenna directly to the RX1 input on the Orion board? That'll narrow it down some.

Bottom line: no one can give you a definitive answer. Best course of action is to get the schematics from the factory, a signal generator and an oscilloscope, and see where the signal stops.
kb3bf
Posts: 9
Joined: Mon Mar 02, 2020 7:15 pm
Location: columbia Md.

Re: RX2 not same signal level as RX1

Postby kb3bf » Sat Nov 28, 2020 5:40 pm

Hi Scott,

thanks for the fast reply.

Further visual inspection of the Filter Pa board shows D20 blown and shorted to gnd. Found replacements with Arrow.
Not sure if there is more damage; but we'll do more signal tracing. FL7 next to D20 shows IN-OUT continuity.

The black AXICOM relays are not surface mount. Before I remove the PA-Filter board for nihl, will I be able to trace the pins on the bottom side of the board to do signal tracing?

Your suggestion to go the input to the Orion board is a good one which I did not think of, but do you rewire everything outside the case and then try? In the case it does not seem possible.

So far so good, fingers crossed it is only D20.

kb3bf, chris
User avatar
w-u-2-o
Posts: 2910
Joined: Fri Mar 10, 2017 1:47 pm

Re: RX2 not same signal level as RX1

Postby w-u-2-o » Sat Nov 28, 2020 6:13 pm

I don't know if you can follow the traces to reverse engineer things. That's why it would be good to contact the factory for the schematics.

Assuming you have the right cables/adapters it should be no problem to inject a signal directly into the RX1 connector on the Orion board. You will have to disassemble things a bit, of course.
kb3bf
Posts: 9
Joined: Mon Mar 02, 2020 7:15 pm
Location: columbia Md.

Re: RX2 not same signal level as RX1

Postby kb3bf » Sat Nov 28, 2020 6:50 pm

Scott, I have the schematics and I am looking at the three pages of the Filter-Pa board.

What I am not seeing is continuity from center pin Ant1, to pin 3 RL22 but that's probably OK since K8 and K5 need to be energized, since the relay coil symbols are on top of the relay contacts (while some other relay symbols have the energizing coil on bottom).

If that is correct, I will just remove the the blown transient suppressor D20 and put everything back together to resume troubleshooting and order spare parts.
User avatar
w-u-2-o
Posts: 2910
Joined: Fri Mar 10, 2017 1:47 pm

Re: RX2 not same signal level as RX1

Postby w-u-2-o » Sat Nov 28, 2020 9:08 pm

I believe that is correct.
kb3bf
Posts: 9
Joined: Mon Mar 02, 2020 7:15 pm
Location: columbia Md.

Re: RX2 not same signal level as RX1

Postby kb3bf » Sun Nov 29, 2020 2:06 am

Thanks for your help Scott. This Forum is very helpful.

I removed the burnout transient suppressor D20 which was shorted, and all is well now, waiting for replacements.

Apache did a good job installing two transient suppressors (that i have noticed) and at the right places.
I am now installing a dedicated coax relay for the Anan to isolate it from the antenna whenever power is turned off. It will be connect to a dummy load until ready for use. I learned my lesson.

However there was a moment of panic when the rig was reassembled and blew a 30A 12V fuse. There are three identical 12V connectors for both boards and it is easy to get any of them crossed. They should have been keyed differently to prevent that. But thanks to the schematics i was able to rewire it correctly and nothing serious happened.

BTW where are Anans sent to for repair service, back to India?


kb3bf chris
User avatar
w-u-2-o
Posts: 2910
Joined: Fri Mar 10, 2017 1:47 pm

Re: RX2 not same signal level as RX1

Postby w-u-2-o » Sun Nov 29, 2020 11:47 am

In the USA they go to Doug, W5WC for factory service.
sv1jso
Posts: 13
Joined: Wed May 30, 2018 7:06 pm

Re: RX2 not same signal level as RX1

Postby sv1jso » Tue Apr 13, 2021 8:56 am

Like N4XD I observed lower noise floor on second receiver with thetis 2.8.11 in my 7000 dle. The second receiver hears as well as the first one but the noise floor and signals are about 10db lower than the first receiver.
Is easy to check this by unplugging the antennas and watching the noise floor - smeter or moving the antenna from ANT X to RX2
Is this happened to anyone else? Is this default behavior for some reason?


Mike
SV1JSO
User avatar
w-u-2-o
Posts: 2910
Joined: Fri Mar 10, 2017 1:47 pm

Re: RX2 not same signal level as RX1

Postby w-u-2-o » Tue Apr 13, 2021 11:05 am

Mike,

If you've been following the above examples, in every case the problem was a hardware failure of some sort.

N4XD did not report a lower noise floor, he reported lower signal levels. Is that what you are seeing?

Assuming you've done your part in identically configuring both paths in the software and swapping antennas around for testing, your hardware is likely broken, too. If you have not done your part, start there.

73,

Scott
sv1jso
Posts: 13
Joined: Wed May 30, 2018 7:06 pm

Re: RX2 not same signal level as RX1

Postby sv1jso » Tue Apr 13, 2021 12:54 pm

Thanks Scot for the suggestion but everything is 10db down. Noise floor signals everything. Reception as I wrote before is good. The second receiver can decode signals in the noise as the first one.

Mike
SV1JSO
PHILIPASCHECHTER
Posts: 9
Joined: Mon Aug 31, 2020 5:24 am

Re: RX2 not same signal level as RX1

Postby PHILIPASCHECHTER » Wed Apr 14, 2021 9:53 am

Mike,

I have the same exact issue with my new 7000DLE MK2. New to SDRs, I
have searched for a software error, like maybe I missed checking a box I should have checked. Nothing.
I plan to contact Doug.
73, Phil

W0OJ
User avatar
w-u-2-o
Posts: 2910
Joined: Fri Mar 10, 2017 1:47 pm

Re: RX2 not same signal level as RX1

Postby w-u-2-o » Wed Apr 14, 2021 11:09 am

Gents: please let us all know what was broken when you find out. This way we can start to identify any trends.
K1LSB
Posts: 123
Joined: Wed Feb 05, 2020 5:25 pm

Re: RX2 not same signal level as RX1

Postby K1LSB » Wed Apr 14, 2021 12:51 pm

Since Scott asked, I had very poor sensitivity on RX2 (roughly 40 dB down from RX1) on my 7000DLE MKII which I didn't even notice until the warranty period had almost expired. I contacted the factory and they had me send it to Doug W5WC who fixed me up in a jiffy. The problem was a bad filter in the BPF for RX2.

Mark
sv1jso
Posts: 13
Joined: Wed May 30, 2018 7:06 pm

Re: RX2 not same signal level as RX1

Postby sv1jso » Wed Apr 14, 2021 8:50 pm

D22 had a hole on top and it was 10 ohm resistor!! D20 also was dead but not sorted. And I had the idea that I was taking good care of it! I removed the D22 and the second receiver was back to normal. Waiting now for replacement parts.

Mike
SV1JSO
PHILIPASCHECHTER
Posts: 9
Joined: Mon Aug 31, 2020 5:24 am

Re: RX2 not same signal level as RX1

Postby PHILIPASCHECHTER » Sat Apr 17, 2021 12:14 am

HI All,

I reached out to Doug and I wanted to share the response as it could be helpful to someone:


Hi Phil,

Double check that the antenna is plugged into the ‘RX2’ BNC connector and not the ‘ANT 2’ port.

If that’s okay try having the software bypass the BPF for RX2.

<image002.jpg>

73, Doug

Return to “Everything Else: Antennas, Relays, Switches, Power, Grounding, Cooling, etc.”