[Repeater-Builder] Re: Discriminator audio
Hi Bob, [EMAIL PROTECTED] wrote: Distortion is not the only issue in using speaker audio as repeat audio. In many cases there is additional filtering in the speaker audio chain that can degrade repeat audio. I have not run into that being a problem.. in fact in an ideal world the speaker audio in many commercial radios should have the ctcss frequencies removed. The speaker audio should normally be de-emphasized and have the ctcss sub tones removed, which is great news when the transmit radio has its own internal ctcss encoder (for true strip and re-insert ctcss sub tone operation). In the end it has a lot to do with how the radio was designed. An Amen from the crowd... I once built a barebones system using a GE MVP with speaker audio going straight into the mic input using only an 8 ohm load resistor, coupling capacitor resistive divider to get the level right. It did sound quite good, but I suspect this is more the exception than the norm. Bob NO6B Shouldn't be... many people seem to get freaked out about the transmit radio audio input being at very low mic-level/values, which is not always the case. Some radios (Midland Syntech and XTR) have a much higher mic input value (their hand mics have a pretty decent internal preamplifier circuit) and work very primo with terminated speaker audio connections. Terminated speaker audio is a very viable option if you need to go that route. Picking level-setting part values, which result in running the volume control operated in the lower 1/3 of it's normal range often keep the audio amplifier distortion levels well under control. And... all of this is pretty easy to do using simple connections. The major trick is to keep magic fingers from adjusting the volume control(s) once you set it to a desired value. cheers, skipp In many/most cases the reported speaker output distortion is not anything to get excited about... it can be/is often quite usable and in many/most cases un-noticed by most repeater system users. In a basic repeater system terminated speaker audio remains a very viable option.
Re: [Repeater-Builder] Re: Discriminator audio
I haven't messed with Hamtronics repeaters for about 20 years, but at the time they specified coupling speaker audio, and their repeaters sounded really flat and clean. 73, Paul, AE4KR - Original Message - From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, December 10, 2007 10:19 PM Subject: Re: [Repeater-Builder] Re: Discriminator audio At 12/10/2007 11:11, you wrote: In many/most cases the reported speaker output distortion is not anything to get excited about... it can be/is often quite usable and in many/most cases un-noticed by most repeater system users. In a basic repeater system terminated speaker audio remains a very viable option. Distortion is not the only issue in using speaker audio as repeat audio. In many cases there is additional filtering in the speaker audio chain that can degrade repeat audio. In the end it has a lot to do with how the radio was designed. I once built a barebones system using a GE MVP with speaker audio going straight into the mic input using only an 8 ohm load resistor, coupling capacitor resistive divider to get the level right. It did sound quite good, but I suspect this is more the exception than the norm. Bob NO6B
Re: [Repeater-Builder] Re: Discriminator audio
The R-100 has two fixed outputs available. De-emphasized audio is available on terminal E1, but I would not recommend using it. The audio level is only about 100mv p-p at this connection. A better choice would be the Discriminator Audio output on terminal E5. This is capable of 2 volts p-p and I believe the RLC controller would like to have 1 volt p-p at it's input. If you use the discriminator output of the R-100 you will have to look into the RLC manual and find the jumper option to add the de-emphasis filter to the circuit. It's in the manual for the RLC under Connecting the Receiver Audio. 73, Joe, K1ike mickupi wrote: - -- I am using the R-100 Hamtronics receiver. Mick
[Repeater-Builder] Re: Discriminator audio
Hi Mick, In your case the best choice is probably based on your controller being able to take discriminator audio direct. Most any controller designed to operate from discriminator audio would be the most practical option and you would be able to use the speaker audio for local at-site monitoring. We would assume the repeater controller using a discriminator input option would properly handle the audio, which includes any ctcss (sub tone) information on the received recovered signal. There are actually at least three audio source options for most receivers like the Hamtronics Units. You can use/tap the discriminator output, tap/use the high side of the volume pot (control), which has squelched and de-emph audio but sometimes no ctcss filtering and third ... the speaker output terminated onto a resistor. In many/most cases the reported speaker output distortion is not anything to get excited about... it can be/is often quite usable and in many/most cases un-noticed by most repeater system users. In a basic repeater system terminated speaker audio remains a very viable option. So you get three mints in one... cheers, s. mickupi [EMAIL PROTECTED] wrote: I am running a Hamtronics receiver on our 53.090/52.090 repeater. Should I use discriminator audio or squelched audio from the speaker. Our Links RLC4 will use either one. Mick
Re: [Repeater-Builder] Re: Discriminator audio
At 12/10/2007 11:11, you wrote: In many/most cases the reported speaker output distortion is not anything to get excited about... it can be/is often quite usable and in many/most cases un-noticed by most repeater system users. In a basic repeater system terminated speaker audio remains a very viable option. Distortion is not the only issue in using speaker audio as repeat audio. In many cases there is additional filtering in the speaker audio chain that can degrade repeat audio. In the end it has a lot to do with how the radio was designed. I once built a barebones system using a GE MVP with speaker audio going straight into the mic input using only an 8 ohm load resistor, coupling capacitor resistive divider to get the level right. It did sound quite good, but I suspect this is more the exception than the norm. Bob NO6B
