Re: [Repeater-Builder] White Noise on Micor TX
On Sun, 23 May 2010, Tim - WD6AWP wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Are you set up for transmitting a PL/CTCSS? -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] White Noise on Micor TX
Hi Tim, Might the RX be hearing the TX? Doug - GM7SVK On 23/05/2010 04:10:37, Tim - WD6AWP (tisaw...@gmail.com) wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP Yahoo! Groups Links
Re: [Repeater-Builder] White Noise on Micor TX
I had this on a Mastr II and solved it by adding a resistor across the audio input to the exciter - I think I used a 100K, but you could experiment. It originally sounded like squelch noise leakage, but it wasn't. Chuck WB2EDV - Original Message - From: Tim - WD6AWP tisaw...@gmail.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, May 23, 2010 12:10 AM Subject: [Repeater-Builder] White Noise on Micor TX I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.819 / Virus Database: 271.1.1/2890 - Release Date: 05/22/10 14:26:00
Re: [Repeater-Builder] White Noise on Micor TX
At 5/22/2010 21:10, you wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP I never heard of this problem on a Moto radio, but the G.E.s will do this if the CG (PL) input on the TX is left unloaded. Somehow a bit of the RX's discriminator output leaks into the phase modulator. Apparently it has a very high impedance, as any load on it eliminates the problem. You might loading the PL input on the Micor see if it has the same effect. Is this a VHF or UHF radio, is it currently on the air? (I can probably hear it from here) Bob NO6B
Re: [Repeater-Builder] White Noise on Micor TX
Yes, it has a stock Motorola PL encode board. I think the noise was there before I installed it. -- :wq Tim
Re: [Repeater-Builder] White Noise on Micor TX
Has the noise been there all along? It may be just the nature of the beast. There is an article on the RB web site about modifying a mobile audio squelch board to work in a base/repeater station, one of the benifits to doing so is the better muting of audio from the receiver, this is because there are two shunt switches in the squelch chip and the mobile configuration uses both to mute the audio, in the repeater/base station configuration one of the shunt switches is used for station control like cos and not as affective at totally muting the audio. As designed the repeaters with their internal controller never had much hang time so it wasn't as noticeable. tom On 5/23/2010 12:10 AM, Tim - WD6AWP wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP Yahoo! Groups Links
Re: [Repeater-Builder] White Noise on Micor TX
Tom, I believe he said that with the controller disconnected, and using local PTT, it still does it. That should take the receiver completely out of the equation, leaving only the exciter as the likely culprit. I'd suggested adding a resistor from ground to audio high on the exciter to see if that helps. It did for me on one Mastr II that I had. Might be something similar on his Micor. Certainly a very simple thing to try. Bob already asked about the PL board as that's another possible candidate, but was informed that there is a PL board installed already. Chuck WB2EDV - Original Message - From: Thomas Oliver tsoli...@tir.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, May 23, 2010 12:21 PM Subject: Re: [Repeater-Builder] White Noise on Micor TX Has the noise been there all along? It may be just the nature of the beast. There is an article on the RB web site about modifying a mobile audio squelch board to work in a base/repeater station, one of the benifits to doing so is the better muting of audio from the receiver, this is because there are two shunt switches in the squelch chip and the mobile configuration uses both to mute the audio, in the repeater/base station configuration one of the shunt switches is used for station control like cos and not as affective at totally muting the audio. As designed the repeaters with their internal controller never had much hang time so it wasn't as noticeable. tom On 5/23/2010 12:10 AM, Tim - WD6AWP wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP
RE: [Repeater-Builder] White Noise on Micor TX
Has it been established whether the Micor station was originally built as a repeater, or is it a base station that has been converted into a repeater? A repeater station comes with a great deal of filter components added to the two interconnect boards, as well as extra shielding over the unified chassis shelves. A lot of strange things can happen if the shield plates are left off, or are not fastened with all screws. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Chuck Kelsey Sent: Sunday, May 23, 2010 9:55 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] White Noise on Micor TX Tom, I believe he said that with the controller disconnected, and using local PTT, it still does it. That should take the receiver completely out of the equation, leaving only the exciter as the likely culprit. I'd suggested adding a resistor from ground to audio high on the exciter to see if that helps. It did for me on one Mastr II that I had. Might be something similar on his Micor. Certainly a very simple thing to try. Bob already asked about the PL board as that's another possible candidate, but was informed that there is a PL board installed already. Chuck WB2EDV - Original Message - From: Thomas Oliver tsoli...@tir.com mailto:tsoliver%40tir.com To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Sunday, May 23, 2010 12:21 PM Subject: Re: [Repeater-Builder] White Noise on Micor TX Has the noise been there all along? It may be just the nature of the beast. There is an article on the RB web site about modifying a mobile audio squelch board to work in a base/repeater station, one of the benifits to doing so is the better muting of audio from the receiver, this is because there are two shunt switches in the squelch chip and the mobile configuration uses both to mute the audio, in the repeater/base station configuration one of the shunt switches is used for station control like cos and not as affective at totally muting the audio. As designed the repeaters with their internal controller never had much hang time so it wasn't as noticeable. tom On 5/23/2010 12:10 AM, Tim - WD6AWP wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP
Re: [Repeater-Builder] White Noise on Micor TX
Chuck, I did over look that part about being disconnected. Is it present when you have a full quieting signal on the rx input? He may still have an audio path feeding the tx. How about pulling the audio squelch board and trying the local ptt? tom On 5/23/2010 12:54 PM, Chuck Kelsey wrote: Tom, I believe he said that with the controller disconnected, and using local PTT, it still does it. That should take the receiver completely out of the equation, leaving only the exciter as the likely culprit. I'd suggested adding a resistor from ground to audio high on the exciter to see if that helps. It did for me on one Mastr II that I had. Might be something similar on his Micor. Certainly a very simple thing to try. Bob already asked about the PL board as that's another possible candidate, but was informed that there is a PL board installed already. Chuck WB2EDV - Original Message - From: Thomas Olivertsoli...@tir.com To:Repeater-Builder@yahoogroups.com Sent: Sunday, May 23, 2010 12:21 PM Subject: Re: [Repeater-Builder] White Noise on Micor TX Has the noise been there all along? It may be just the nature of the beast. There is an article on the RB web site about modifying a mobile audio squelch board to work in a base/repeater station, one of the benifits to doing so is the better muting of audio from the receiver, this is because there are two shunt switches in the squelch chip and the mobile configuration uses both to mute the audio, in the repeater/base station configuration one of the shunt switches is used for station control like cos and not as affective at totally muting the audio. As designed the repeaters with their internal controller never had much hang time so it wasn't as noticeable. tom On 5/23/2010 12:10 AM, Tim - WD6AWP wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP Yahoo! Groups Links
Re: [Repeater-Builder] White Noise on Micor TX
He indicated that in repeat it was better (less white noise) with an incoming signal, then got worse on the tail. Then he disconnected the controller and still had white noise with local PTT. To me that hints of the exciter not liking a high impedance input, or no load on the mic input. That's why I suggested trying to add some resistance across the mic high and low at the exciter. Chuck - Original Message - From: Thomas Oliver tsoli...@tir.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, May 23, 2010 2:49 PM Subject: Re: [Repeater-Builder] White Noise on Micor TX Chuck, I did over look that part about being disconnected. Is it present when you have a full quieting signal on the rx input? He may still have an audio path feeding the tx. How about pulling the audio squelch board and trying the local ptt? tom
Re: [Repeater-Builder] White Noise on Micor TX
Would the same apply to an MSF2000 base station converted to a repeater? lh On Sun, May 23, 2010 at 1:10 PM, Eric Lemmon wb6...@verizon.net wrote: Has it been established whether the Micor station was originally built as a repeater, or is it a base station that has been converted into a repeater? A repeater station comes with a great deal of filter components added to the two interconnect boards, as well as extra shielding over the unified chassis shelves. A lot of strange things can happen if the shield plates are left off, or are not fastened with all screws. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com] On Behalf Of Chuck Kelsey Sent: Sunday, May 23, 2010 9:55 AM To: Repeater-Builder@yahoogroups.com Repeater-Builder%40yahoogroups.com Subject: Re: [Repeater-Builder] White Noise on Micor TX Tom, I believe he said that with the controller disconnected, and using local PTT, it still does it. That should take the receiver completely out of the equation, leaving only the exciter as the likely culprit. I'd suggested adding a resistor from ground to audio high on the exciter to see if that helps. It did for me on one Mastr II that I had. Might be something similar on his Micor. Certainly a very simple thing to try. Bob already asked about the PL board as that's another possible candidate, but was informed that there is a PL board installed already. Chuck WB2EDV - Original Message - From: Thomas Oliver tsoli...@tir.com tsoliver%40tir.com mailto: tsoliver%40tir.com tsoliver%2540tir.com To: Repeater-Builder@yahoogroups.com Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.comRepeater-Builder%2540yahoogroups.com Sent: Sunday, May 23, 2010 12:21 PM Subject: Re: [Repeater-Builder] White Noise on Micor TX Has the noise been there all along? It may be just the nature of the beast. There is an article on the RB web site about modifying a mobile audio squelch board to work in a base/repeater station, one of the benifits to doing so is the better muting of audio from the receiver, this is because there are two shunt switches in the squelch chip and the mobile configuration uses both to mute the audio, in the repeater/base station configuration one of the shunt switches is used for station control like cos and not as affective at totally muting the audio. As designed the repeaters with their internal controller never had much hang time so it wasn't as noticeable. tom On 5/23/2010 12:10 AM, Tim - WD6AWP wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP
RE: [Repeater-Builder] White Noise on Micor TX
Larry, I know about MSR2000 and MSF5000 stations, but I've never heard of an MSF2000. Most stations that are built for simplex (base) operation lack the filtering that is standard in duplex (repeater) operation. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Larry Horlick Sent: Sunday, May 23, 2010 1:35 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] White Noise on Micor TX Would the same apply to an MSF2000 base station converted to a repeater? lh On Sun, May 23, 2010 at 1:10 PM, Eric Lemmon wb6...@verizon.net mailto:wb6...@verizon.net wrote: Has it been established whether the Micor station was originally built as a repeater, or is it a base station that has been converted into a repeater? A repeater station comes with a great deal of filter components added to the two interconnect boards, as well as extra shielding over the unified chassis shelves. A lot of strange things can happen if the shield plates are left off, or are not fastened with all screws. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com ] On Behalf Of Chuck Kelsey Sent: Sunday, May 23, 2010 9:55 AM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: Re: [Repeater-Builder] White Noise on Micor TX Tom, I believe he said that with the controller disconnected, and using local PTT, it still does it. That should take the receiver completely out of the equation, leaving only the exciter as the likely culprit. I'd suggested adding a resistor from ground to audio high on the exciter to see if that helps. It did for me on one Mastr II that I had. Might be something similar on his Micor. Certainly a very simple thing to try. Bob already asked about the PL board as that's another possible candidate, but was informed that there is a PL board installed already. Chuck WB2EDV - Original Message - From: Thomas Oliver tsoli...@tir.com mailto:tsoliver%40tir.com mailto:tsoliver%40tir.com mailto:tsoliver%2540tir.com To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%2540yahoogroups.com Sent: Sunday, May 23, 2010 12:21 PM Subject: Re: [Repeater-Builder] White Noise on Micor TX Has the noise been there all along? It may be just the nature of the beast. There is an article on the RB web site about modifying a mobile audio squelch board to work in a base/repeater station, one of the benifits to doing so is the better muting of audio from the receiver, this is because there are two shunt switches in the squelch chip and the mobile configuration uses both to mute the audio, in the repeater/base station configuration one of the shunt switches is used for station control like cos and not as affective at totally muting the audio. As designed the repeaters with their internal controller never had much hang time so it wasn't as noticeable. tom On 5/23/2010 12:10 AM, Tim - WD6AWP wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP
Re: [Repeater-Builder] White Noise on Micor TX
A resistor certainly would be easy enough to try. As would popping in a spare exciter if he has one. tom On 5/23/2010 3:01 PM, Chuck Kelsey wrote: He indicated that in repeat it was better (less white noise) with an incoming signal, then got worse on the tail. Then he disconnected the controller and still had white noise with local PTT. To me that hints of the exciter not liking a high impedance input, or no load on the mic input. That's why I suggested trying to add some resistance across the mic high and low at the exciter. Chuck - Original Message - From: Thomas Olivertsoli...@tir.com To:Repeater-Builder@yahoogroups.com Sent: Sunday, May 23, 2010 2:49 PM Subject: Re: [Repeater-Builder] White Noise on Micor TX Chuck, I did over look that part about being disconnected. Is it present when you have a full quieting signal on the rx input? He may still have an audio path feeding the tx. How about pulling the audio squelch board and trying the local ptt? tom Yahoo! Groups Links
Re: [Repeater-Builder] White Noise on Micor TX
Eric, I'm usually dyslexic on Yundas! It's a MSR2000. About 12 years ago I converted a base station variant to a repeater. As I recall I had some difficulty configuring it; i.e. there were some jumpers to add and remove, but thus puppy has been trucking along at a very busy site and nary a problem, 5 mHz split on VHF. Because it has been working so well I was wondering if some the older mega-kg Motos were produced with equal filtering in all variants. I was just luck, I guess. lh On Sun, May 23, 2010 at 4:47 PM, Eric Lemmon wb6...@verizon.net wrote: Larry, I know about MSR2000 and MSF5000 stations, but I've never heard of an MSF2000. Most stations that are built for simplex (base) operation lack the filtering that is standard in duplex (repeater) operation. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com] On Behalf Of Larry Horlick Sent: Sunday, May 23, 2010 1:35 PM To: Repeater-Builder@yahoogroups.com Repeater-Builder%40yahoogroups.com Subject: Re: [Repeater-Builder] White Noise on Micor TX Would the same apply to an MSF2000 base station converted to a repeater? lh On Sun, May 23, 2010 at 1:10 PM, Eric Lemmon wb6...@verizon.netwb6fly%40verizon.net mailto:wb6...@verizon.net wb6fly%40verizon.net wrote: Has it been established whether the Micor station was originally built as a repeater, or is it a base station that has been converted into a repeater? A repeater station comes with a great deal of filter components added to the two interconnect boards, as well as extra shielding over the unified chassis shelves. A lot of strange things can happen if the shield plates are left off, or are not fastened with all screws. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.comRepeater-Builder%2540yahoogroups.com [mailto:Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.comRepeater-Builder%2540yahoogroups.com ] On Behalf Of Chuck Kelsey Sent: Sunday, May 23, 2010 9:55 AM To: Repeater-Builder@yahoogroups.com Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.comRepeater-Builder%2540yahoogroups.com Subject: Re: [Repeater-Builder] White Noise on Micor TX Tom, I believe he said that with the controller disconnected, and using local PTT, it still does it. That should take the receiver completely out of the equation, leaving only the exciter as the likely culprit. I'd suggested adding a resistor from ground to audio high on the exciter to see if that helps. It did for me on one Mastr II that I had. Might be something similar on his Micor. Certainly a very simple thing to try. Bob already asked about the PL board as that's another possible candidate, but was informed that there is a PL board installed already. Chuck WB2EDV - Original Message - From: Thomas Oliver tsoli...@tir.com tsoliver%40tir.com mailto: tsoliver%40tir.com tsoliver%2540tir.com mailto:tsoliver%40tir.com tsoliver%2540tir.com mailto: tsoliver%2540tir.com tsoliver%252540tir.com To: Repeater-Builder@yahoogroups.com Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.comRepeater-Builder%2540yahoogroups.com mailto:Repeater-Builder%40yahoogroups.comRepeater-Builder%2540yahoogroups.com mailto:Repeater-Builder%2540yahoogroups.comRepeater-Builder%252540yahoogroups.com Sent: Sunday, May 23, 2010 12:21 PM Subject: Re: [Repeater-Builder] White Noise on Micor TX Has the noise been there all along? It may be just the nature of the beast. There is an article on the RB web site about modifying a mobile audio squelch board to work in a base/repeater station, one of the benifits to doing so is the better muting of audio from the receiver, this is because there are two shunt switches in the squelch chip and the mobile configuration uses both to mute the audio, in the repeater/base station configuration one of the shunt switches is used for station control like cos and not as affective at totally muting the audio. As designed the repeaters with their internal controller never had much hang time so it wasn't as noticeable. tom On 5/23/2010 12:10 AM, Tim - WD6AWP wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP
[Repeater-Builder] White Noise on Micor TX
I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Anyone ever run into this before? Tim WD6AWP
