Remote Rig

RRC 1258 Support in English => General discussion forum => Topic started by: G3UEG on 2010-08-14, 22:20:36

Title: TS-480 RFI - more information
Post by: G3UEG on 2010-08-14, 22:20:36
The receive side of my system has been superb, but I have had serious problems with RFI when transmitting and have had to install a large number of ferrites to get to the stage of being able to transmit at the 100w level.

My approach has been to back off the various gains both in the radio as well as in the RRCs, so there is virtually no ALC being triggered, with just one led occasionally 

The interesting discovery is that most of the problem is when using the internal speech processor.  Testing has been on 80m as this is the only band I can hear myself on from my home operating location..  (100Km away)

Having got the SPE amplifier working I have discovered the following:-
1)  I can transmit 400w on CW
2)  I can transmit 400w on SSB as long as the PROCESSOR IS OFF
3)  With the processor on (even with low levels of processing) I cannot transmit more than about 50w

The RFI effect I am getting is a continuous "clicking" at about 2 per second which generates significant RF output. This happens as soon as I press the PTT and before I start speaking, and continues when I start speaking.

Does anyone have any ideas what I can do to solve this problem??
I have wondered about cutting the audio (RJ45 cable) and putting a 1:1 transformer in the mic circuit
Am not sure whether I should do anything else on the other wires.

Question for Mike..
What effect on the RRC performance is there by further reducing the Codec Input gain??

73,
Dave, G3UEG

Title: Re: TS-480 RFI - more information
Post by: M0BPQ on 2010-08-15, 21:05:36
I can pretty much repeat the problems Dave is reporting with My TS-480 and RRC V2. When the comp is on, SSB is unusable. Should I do the op amp mod?

I also have an RRC mk1 and a IC-706G that I use on VHF/UHF SSB and I get excellent audio reports with that, even at 400W with the antenna only 5m away. I shall try that radio on HF to see if I get an RFI problem or if it is limited to the 480/MKII combination.

If anyone has any siggestions for Dave's problem please post it here so I can try it too.

73
Steve
Title: Re: TS-480 RFI - more information
Post by: G3UEG on 2010-08-15, 21:45:19
Hi Steve,

I would be very interested in the result of your proposed test with the IC706, are you planning to try it with the V1 or V2 RRC?

I hope Mike can suggest the correct course of action re the Op-amp mod..

73,
Dave, G3UEG
Title: Re: TS-480 RFI - more information
Post by: W6SA on 2010-08-16, 01:43:51
Have you turned off the pre-amp in the RemoteRig settings?  I had the same problem and the clicking would put the rig on the air before I even breathed into the mike. I turned it off and no more problems.

73,

Walt, W6SA
Title: Re: TS-480 RFI - more information
Post by: G3UEG on 2010-08-16, 15:29:59
Hi Walt,

Thanks for the suggestion, but the pre-amp has been off from the beginning.  Also I have reduced the codec input gain down from the recommended level to try and tame it further.

Are you using the RRC V2? and have you done the op-amp mod?

73,
Dave, G3UEG
Title: Re: TS-480 RFI - more information
Post by: W6SA on 2010-08-16, 17:06:24
Hi Dave,

Yes, I have version 2.  I admittedly have only made a couple of contacts while testing.  Audio reports were good with the pre-amp off and I have not seen a need to make the mod at this time.  Perhaps it will be necessary once I get into full operation.

I bought this unit for travel purposes and I don't do that very often.  I will probably have more use for it as a second operating position when the xyl insists I join her in the TV room and I want to try to work a DXpedition.

XYL just had major surgery so have not had the time to take it to a hotspot to try it out now that I believe I have finally worked all the bugs out of the basic setup.  Hope to do that later this week.

Good luck with your problem.

73,

Walt,  W6SA
Title: Re: TS-480 RFI - more information
Post by: HB9AZT on 2010-08-17, 12:46:20
Hi Dave

Had an ACOM2000A at a remote location, running 1 KW out without any problems. Had to replace it temporarily due to maintenance by an Expert and lot of rfi-problems came up, computer crashed etc. Had to put ferrites in every line going to the expert, especially the power line is not clean and spreading rf in the rack. Amp is carrying CE-sign, but this doesn't help against RFI:-(

73 de Mark, HB9AZT

Title: Re: TS-480 RFI - more information
Post by: M0BPQ on 2010-08-20, 15:26:21
Dear All,

I have tried my IC-706g/RRC v1 on HF and it works just fine. The same PSU/antenna with the TS480/RRC v2 (preamp off) gives the problem that Dave describes above. I guess the obvious solution is to switch the RRCs around and see what happens, but I hate to break a working system...

More news if I get time and courage to move things around.
73
Steve, M0BPQ
Title: Re: TS-480 RFI - more information
Post by: G3UEG on 2010-08-21, 13:39:32
Hi Steve,

Useful info from the test.  I realize it would be pain, but two more tests..

1) TS-480 and RRCV1 and
2) IC706 with RRCV2

would be **VERRRRY** interesting.  I would be willing to help if you would like..

73,
Dave, G3UEG
Title: Re: TS-480 RFI - more information
Post by: sm0mdg on 2010-08-23, 08:34:49
The receive side of my system has been superb, but I have had serious problems with RFI when transmitting and have had to install a large number of ferrites to get to the stage of being able to transmit at the 100w level.

Does anyone have any ideas what I can do to solve this problem??

I had the same problem but where able to cure most of it. I am now running the station at the gain/ALC levels intended and only have RFI problems on 40 meter which I credit to the antenna layout rather than the Remoterig / TS-480 combination. In short the fix was to turn off the "Codec inp preamp" setting in Remoterig and compensate gain in the radio.

Have a look at this message;

http://www.styrefors.se/sm2oan/remote/forum/index.php?topic=242.msg741#msg741

My MkII boxes have not been modified in the audio chain as suggested by Mike, I don't dare to mess with it as it works quite well right now.

73 de Björn,
SM0MDG
SE0X
Title: Re: TS-480 RFI - more information
Post by: G3UEG on 2010-08-23, 15:59:12
Thanks for all the comments..

I don't get any problems when operating seriously in contests when I am actually at the remote site operating in person and running things at max!!
I have acquired an RF clip-on meter and cannot detect any RF current on the 50% of the leads I checked..
(I will re-test the meter itself!!!)

Bjorn..
The codec input pre-amp has been switched off from very early on.

Mark..
Could you describe more fully what you had to do to your SPE amp to "tame" it...   I have wound the mains cable abt 6 turns through an FT240-43 core at the amp end, plus a couple of clip-on cores at the other end..  I have also wound the PTT lead many times through a smaller core.  I have several clip-on cores on the RS232 lead.  I have put an RF common mode choke in the coax feed to the external antenna switch.

I went to the site yesterday again and as well as working on the amp as described above.. I have changed some of the ferrites of unknown spec to ones with Type 31 ferrite, which has higher loss than type 43.
The short RJ12 lead has three cores.
The Aux/Mic lead has 9 cores
The dc supply is wound many times round a torroid.
There are several clip-on ferrites on the ethernet cable and RS232 cable.

All of this made a very slight improvement..  I can now TX 100w barefoot with the processor on, and about 200w with the processor off.. both of these about twice what they were before..

Any thoughts whether there would be any point putting the radio RRC inside a metal box??

That is now 5 trips and 1000Kms to try to solve this problem......

73,
Dave, G3UEG
Title: Re: TS-480 RFI - more information
Post by: LA7THA on 2010-09-04, 02:39:27
Hi Gents

I use Remoterig V1 TS480 and Acom 2000. Have used 1 Ton of ferite, decoupling capacitors etc. My wiring between RCC and Ts480 is all Shielded.
I also noticed that when Proc is on the audio out geting usles.
Hope someone find a solution on this

73 de Rune LA7THA
Title: Re: TS-480 RFI - more information
Post by: on4iq on 2010-09-08, 11:06:35
I'm using a brand new ts-480, even with low power (<10watts) the audio is poor and levels extremely low. I'm not sure if its RFI or another issue. Has anyone similar issues.  When I connect the ts2000 with remote panel it all works OK and audio is really fine.
Title: Re: TS-480 RFI - more information
Post by: PA0TCA on 2010-09-08, 14:41:55
Are you sure that you have not switched the common ground (gnd)  and the mike ground (egnd)
Title: Re: TS-480 RFI - more information
Post by: G3UEG on 2010-09-08, 17:07:32
MIKE - Please help..

There are a significant number of us having the same problem. 

A number of questions have been asked to which no answers have been forthcoming,  I will summarise them here and would be grateful for some answers.

1)  What is the spec of the jumper wires.  I want to redo the jumpers just in case there is a bad connection.  The wires bend very easily and are difficult to re-use once they are bent?

2)  Would doing the mic gain mod help overcome the problems we are having?

3)  Would it help to put the RRC in a screened box?

4) Would it help to put a 1:1 decoupling transformer in the mic connection between the RRC and Rig?

5)  There are a number of errors and inconsistencies in the Kenwood documentation for the RJ45 mic connector 
    a) pin numbering is non-conventional
    b) the mic ground and system ground pins are swapped round in the User Manual
Can you confirm that the wiring schematic for the RJ45 lead from RRC to Rig,   and the jumper wiring diagrams are correct bearing in mind these errors.

73,
Dave, G3UEG
Title: Re: TS-480 RFI - more information
Post by: on4iq on 2010-09-08, 20:51:28
OK, I have found a solution to my issues, I opened the kenwood handmike to check the connections.
In the connector where 2 blue wires, very confusing eh?

measured it and:
middle blue wire on pin 4 is the ground (micro gound) , had this one inversed with the other blue wire
Have 100watts rf free now.
Mike schematic for ts480sat is correct
1 up (blue)
2 N.C. (yellow)
3 micro (white)
4 mic gnd (blue, or should i say shielding of the cable)
5 PTT (grey)
6 PTT GND (green)
7 NC
8 DWN (red)

I have following menu setting:
1. Select DSP Transmission Equalizer (Menu 19) = Hb2.
2. Select Transmitter Filter Bandwidth (Menu 20) = 2.4 KHz.
3. Microphone Mic = 70.
4. Select Processor = ON. Processor input = 65, Processor output = 45
Title: Re: TS-480 RFI - more information
Post by: sm2o on 2010-09-09, 09:24:55
Hi see answers below

1)  What is the spec of the jumper wires.  I want to redo the jumpers just in case there is a bad connection.  The wires bend very easily and are difficult to re-use once they are bent?

EKUX red 0,28mm² diam 0,6 mm

2)  Would doing the mic gain mod help overcome the problems we are having?

No it has nothing do to with RFI, but the settings has to match, to get the  right levels.

Have you tried to increase the LF-levels trough the system so you can reduce the mic gain on the radio, probably it get less sensitive to RF with lower mic gain ?

3)  Would it help to put the RRC in a screened box?

No my experience is that this is an error in the TS-480 which causes this problem. The engineer must have had a bad day when developing the TS-480 mic amplifier. The problems are caused by ground problems. Im not aware of any of these problem with any other rig, even Kenwood rigs. If you have RS-232 ports connected to the RRC, test to remove them, ground loops via the RS-232 eq. get things worse also.

4) Would it help to put a 1:1 decoupling transformer in the mic connection between the RRC and Rig?

No,there is already a 1:1 transformer in the RRC ( see pdf.manual). I think issolating the other signals would be more effecive but it's not that easy of course

5)  There are a number of errors and inconsistencies in the Kenwood documentation for the RJ45 mic connector
    a) pin numbering is non-conventional
    b) the mic ground and system ground pins are swapped round in the User Manual
Can you confirm that the wiring schematic for the RJ45 lead from RRC to Rig,   and the jumper wiring diagrams are correct bearing in mind these errors.

As far as I know my drawings are correct, I understand from this forum other people has verified it also.

73,
Mike
Title: Re: TS-480 RFI - more information
Post by: G3UEG on 2010-09-09, 12:23:30
Hi Mike,

Thank you for the clear answers.

I will have one more attempt to get it working before I give up..

I think I shall strip everything down and start again.  Of the things you have mentioned, I shall
1)  Renew the jumpers carefully
2)  Remove the SPE amp connections inc the RS232
3)  Increase the mic levels through the system and reduce the mic gain.
4)  try placing everything on a large flat aluminium earth plate.

Finally can anyone confirm whether there is anything at the control end that can be done to mitigate the problems (other than adjusting the gains as suggested above)

Can anyone explain why if it is a problem with the TS-480, why the problem does not show (even at max power with amp)  when using the standard hand mic or a Heil headset direct into the rig when operating it locally??

73,
Dave, G3UEG
Title: Re: TS-480 RFI - more information
Post by: sm2o on 2010-09-09, 13:55:26
Hi

Nothing can be done at control end besides adjusting gain

When using the orginal mic you have it totaly issolated by the plastic housing thats why it doesn't show any problem.

I will try to spend some time to make a Issolation board where all signals inlcuding the RS-232 ports are issolated

but I can't say when it's finnished.

73 de mike
Title: TS-480 RFI - problem. The reason are found
Post by: sm2o on 2010-09-15, 09:40:22
After Daves G3UEG continued mails about this Issue ( thank you) I decide to investigate this deeper, and we have now found the reason why some people using TS-480 have problems with RFI and other not.

There are two different configurations of the Mic connector in the TS-480. At some point of the production they have swapped Mic-gnd and Chassi-gnd. There are no known way to find out when they have changed from serial number etc. I don't even now which one is the new one or if it is different between HX and SAT, but I guess that "Connection type 1" is in new radios.

If you have problem with RFI at your TS-480 setup try to change the strapping (check at the website).

If you want to go deeper...

The simplest way is to measure with and ohm meter before doing the strapping.  Do not connect anything to power. Open the Radio-RRC, remove the red straps, connect the supplied patch cable between the Radio-RRC and the Mic-Input of the radio. Measure with and good ohm meter between the point marked 6 at the strapping area and a chassi screew on the TS-480. If you get less than 1 ohm you have connection type 1. From the pin marked 4 you should have about 3 ohm to chassi. If you get the opposit values you have connection type 2. After you have decide which connection type you have you can do the strapping according to the pictures on the website.

A comment from Kenwood would of course be interesting...

info on website http://www.remoterig.com/en/ts480anp.htm

73 de mike
Title: Re: TS-480 RFI - more information
Post by: sm2o on 2010-09-15, 21:04:39
Dave got it confirmed today, from someone near Kenwood

Quoting his email

"
 – I’ve checked this and can confirm that the mic socket should be wired as pin 3 = common ground and pin 5 = mic ground.  This matches our other RJ-45 mic sockets in the VHF/UHF mobiles TM-D710E etc., and is shown in the Instruction Manual.

But….in earlier production TS-480SAT/HX models from serial number 70599999 or below, the connection "MCG" (Common GND) was physically wired to pin 5 and "MSG" (MIC GND) was wired to pin 3 in the mic socket.  This was shown in the Service Manual.

From serial number 70600056 onwards, the pattern of the PCB was corrected at the factory and the normal microphone connections reinstated.

Unfortunately our colleagues in the Head Office dept that write the Manuals haven’t yet produced an amended version of the Service Manual and it still shows the “wrong” wiring (i.e. the incorrectly laid-out wiring that was actually in the earlier radios) as opposed to the corrected production version with the “right” wiring as per current radios.

This could cause some confusion to owners as later radios will not match the earlier Service Manual – in this case radios after 70600056 are correct and the Service Manual is wrong.  The Instruction Manual has always shown what should be the correct pin-outs."

I’ll take this up with our contacts here to pass back to Japan as the Service Manual needs updating.

/mike
Title: Re: TS-480 RFI - more information
Post by: sv1elf on 2010-09-16, 15:34:32
Try to change the power suuply from the receive side , change it with a switch mode .
Use to have the same problem until change the power supply
Title: Re: TS-480 RFI - more information
Post by: LA7THA on 2010-10-07, 13:12:41
Did the change on my cable GND/GNDE and all Problem now gone, no bad modulation and also i can use PROC in the radio and modulation is Good:-)
Title: Re: TS-480 RFI - more information
Post by: HB9CVN-4F3CV on 2019-04-17, 13:13:48
hi,

getting very confused here.

I have opened the MIC and it is wired as ON4IQ wrote. The white cable is on pin 3 and comes directly from the mic capsule. I assumed that the mic ground is the blue one, on position four.

But the guy from Kenwood says something different. According to him pin 3 is the common ground.

Can anyone put me on the right track??

This is frustrating, the very last thing missing in order to complete the installation, which should be straightforward is driving me crazy...
Title: Re: TS-480 RFI - more information
Post by: sm2o on 2019-04-18, 09:44:27
it's never recomendable to connect a PC direct to a Radio or to Remoterig. To avid problems with hum and noise, use a isolated interface like signallink or make an own interface with transformers and optocouplers to isolate the PC.

73 de mike

Title: Re: TS-480 RFI - more information
Post by: HB9CVN-4F3CV on 2019-04-19, 21:17:16
uderstood. Will get a signallink or similar device

thanks Mike.