Author Topic: Low audio + lf-hiss FT-2000 twin  (Read 18931 times)

SA0IAT

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Low audio + lf-hiss FT-2000 twin
« on: 2012-03-04, 19:18:51 »
Hi all!
Just set up my FT-2000 installation today. Finally managed to get it working more or less OK, but the volume from the radio is very low. The first beep - when the radio comes up - is very loud and clear (i believe remote rrc produces this?).
There is also a very audiable LF-hiss, which is present also when the radioīs volume is turned down. When I turn the volume all the way clockwise itīs somewhat decent, but it does not seem normal to use such a high volume setting on the radio...

All this indicates that audio from the radio to the radio-RRC is too low. But canīt come to think about what could cause it? Did I miss some setting?

Ideas anyone?

PS. I tried alot of different settings for codec, and confirm attunation is set to 255 on radio settings...

sm2o

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #1 on: 2012-03-04, 23:16:37 »
The audio input to the Radio-RRC are made for "Speaker level" not line out. If you connect it to the phones output or speaker output it will be OK

73 de mike

SA0IAT

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #2 on: 2012-03-05, 09:20:21 »
Itīs connected to the phones jack (on the front of the radio)... Headphones sounded loud and clear in that jack before installation of the RRC, also with a low volume setting.

dj0qn

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #3 on: 2012-03-05, 10:29:53 »
Yes, I have the same problem, also plugged into the headphone jack on the front of the FT-2000.

I have reported this problem before: http://www.remoterig.com/forum/index.php?topic=958.msg3899#msg3899

It makes no difference how JMP4 is set.

73,
Mitch DJ0QN / K7DX

sm2o

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #4 on: 2012-03-05, 11:28:04 »
The load on the Audio input to the Radio-RRC is 50 ohm. If the radio can't produce enough audio with 50 ohm load  the levels will be low. There is nothing which can be changed by jumpers. I have not noticed any problems with the levels when we tested with FT-2000, but we do not have any FT-2000s now to test with. Test to use the speaker output on the back instead.

/mike

SA0IAT

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #5 on: 2012-03-05, 14:06:46 »
OK, Iīll try the rear jack (but is that stereo? - or Iīll miss the feature with subreceiver on separate audio channel).

Or did you already try that, Mitch?

Iīll probably not get to the radio until next weekend....

SA0IAT

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #6 on: 2012-03-06, 14:49:08 »
I did some reading and it seems indeed the output on the FT-2000 is a bit low. Speaker jack would maybe work better, but from I have understood volume controls do not affect the speaker jack output. Also it is a mono jack...

Still itīs strange that it worked OK when you tested it, Micke?

I guess a solution would be to amplify the signal before the radio-rrc.... I can actually try to play arround with this at home since I have a pair of "standard" RRC-1258īs at home (can I hook these up without a radio connected - i.e. just the audio from FT-2000 connected to radio-rrc? Any manual connection command?)

sm2o

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #7 on: 2012-03-07, 15:16:31 »
I tested with a FT-950 which I have here, the output in the headset jack is 10 dB lower than the speaker output when connected to the RRC ( I do not know if it is the same in the FT-2000). With the volume at 12 o'clock and a speaker direct to the speaker jack on the Control-RRC it's still to high to listen to  a carrier when the Radio-RRC  is connected to the speaker jack. But anyhow you can compensate for those -10 dB by setting "codec inp gain" in the Radio-RRC to 13 (13x0,075=9,75). Another way is to remove one or both of the 100 ohm load resistor(s) in the Radio-RRC to reduce the load.

73 de mike

SA0IAT

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #8 on: 2012-03-09, 09:47:38 »
Thanks for your efforts! Super customer service as always  ;)

Removing the load resistors is the better option for me I think, since I like to have the twin/stereo option which is only available through headphone jack.
BTW are these the R102 and R103? Where do I find the on the PCB? And it is just about removing them, no change for other values?


PS. Funny to have the conversation in English, but I thought the thread will be more relevant for more users here   ;)

dj0qn

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #9 on: 2012-03-12, 09:32:42 »
Hi Guys,

I am just catching-up on the reflector. For some reason, I no longer get e-mails to tell me about new postings.

Thanks for verifying that I was not crazy the whole time. I don't get to the remote station very often, so I changed
the "codec inp gain" to 13 and will see if that works better. Since I have a new project that keeps me out of my home
office most of the time, I will try it out this evening or tomorrow evening.

73,
Mitch DJ0QN / K7DX

sm2o

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #10 on: 2012-03-12, 10:08:11 »
OK

Use the RSS that's perfect, and you can activate RRS in your email program so you got all posts direct.

73 de mike

Jan (Microbit)

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #11 on: 2012-03-12, 12:35:24 »
I am just catching-up on the reflector. For some reason, I no longer get e-mails to tell me about new postings.
Thanks for pointing this out! We had forgotten to reconfigure the mail sending when moving the forum. It should now work.
« Last Edit: 2012-03-12, 13:39:03 by Jan (Microbit) »
Always include type of hard/software and version when asking for support.

dj0qn

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #12 on: 2012-03-12, 13:53:22 »
Thanks for fixed the mails. I have been using RSS in parallel, but it is also buggy. It often will show a bunch of
old posts as new ones. It may be a compatibility issue with my RSS reader, since it is pretty fickle.

73,
Mitch DJ0QN / K7DX

Jan (Microbit)

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Re: Low audio + lf-hiss FT-2000 twin
« Reply #13 on: 2012-03-12, 14:12:13 »
Thanks for fixed the mails. I have been using RSS in parallel, but it is also buggy. It often will show a bunch of
old posts as new ones. It may be a compatibility issue with my RSS reader, since it is pretty fickle.

73,
Mitch DJ0QN / K7DX
Does not occur in my RSS reader, so maybe is something "in your end".
Always include type of hard/software and version when asking for support.