Re: [Repeater-Builder] Re: MSR-2000 Deviation Question
I'll testify to that...this one works great with the Squelch Gate interface. de WD7F John in Tucson - Original Message - From: "skipp025" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 27, 2004 4:49 PM Subject: [Repeater-Builder] Re: MSR-2000 Deviation Question Download the MSR2000 to external controller text from my http://www.radiowrench.com/sonic page. It mentions what I feel is a great/better location for your controller audio connections. cheers skipp > "Army Curtis - AE5P" <[EMAIL PROTECTED]> wrote: > No. The output of the controller goes to the Squelch-Gate card, and > through the several stages of audio amplification there before going > on to the exciter. Since that was the way Motorola designed it, it > seemed like the best way to keep it. > > Cheers, > > Army > > --- In Repeater-Builder@yahoogroups.com, "skipp025" <[EMAIL PROTECTED]> > wrote: > > Your driving the transmitter directly from > > your repeater controller..? ... using the > > back plane method? > > > > Sounds like your repeater controller tx output > > doesn't have enough drive power (capacity) to > > directly drive the tx channel element IDC > > (channel element modulator circuit). > > > > Cheers, > > > > skipp > > www.radiowrench.com > > > > > > > "Army Curtis" <[EMAIL PROTECTED]> wrote: > > > Well gang, I have a real interesting problem for you that's > about to > > > drive me nuts. > > > > > > I have a MSR-2000 repeater that I'm putting into the 2M ham band. > > This > > > is one of the radios removed from service by the Ontario > Provincial > > > Police, so it is a Canadian Motorola VHF low split, originally > > > transmitting at 141.xxx. > > > > > > Following the suggestions on the Repeater-Builder web site, I > have > > > converted it to a ham style controller (CAT-700). The radio tunes > > up per > > > the book, with all meter readings very nominal, and it makes full > > power > > > (100 watts) easily. > > > > > > Here's the issue... it will not deviate the transmitter more than > > about > > > 2.7 KHz using a 1 KHz tone before it starts severely distorting. > The > > > problem appears to be in the exciter, which is a TLD9241A. There > is > > a > > > sticker on the exciter shelf that says 0.260 volts = 5 KHz > > deviation. > > > Anytime I put more than about 0.140 volts into the exciter, it > > starts to > > > distort. I am using an IFR-1200S to send and receive the 1KHz > tone, > > and > > > I'm looking at the wave form of the transmitted signal on the > > 1200S. I > > > have verified the 1200S is clean by looking at its output on > another > > > service monitor, and it is very clean to beyond 6 KHz deviation. > I > > have > > > looked at the audio going into the exciter on a scope, and it is > > very > > > clean to up around 0.400 volts, so I would say that the receiver, > > > controller audio, and transmit audio up to the exciter input is > not > > the > > > problem. > > > > > > I tried changing the exciter to another identical board, same > > problem. I > > > changed the channel element to a known good element, same > problem. I > > > have changed the audio input transistor on the exciter board > (Q501), > > > same problem. I have tried to adjust the IDC on the channel > element. > > > While it does change the deviation, it has no effect on the > > distortion. > > > > > > Here is some additional info I just ran down to the shop to > check. > > > Sending a 5 KHz deviation at 1 KHz signal into the IFR1200S from > > another > > > service monitor shows no distortion, so no problem there. > Putting an > > > audio generator right on the audio input to the exciter shows the > > same > > > issue, but here is where it gets interesting. Changing the audio > > > frequency, I am seeing a definite pre-emphasis network somewhere > in > > the > > > exciter, as a tone of 1 KHz gives about 2.7 KHz deviation, but a > > tone of > > > 3.2 KHz gives right at 5 KHz deviation, with NO distortion. > > > > > > So, here's my question. I always thought you set deviation on an > FM > > > transmitter using a 1 KHz tone, setting a maximum deviation of > > about 4.5 > > > KHz. I can see with this exciter that doing that will result in > much > > > more than 5 KHz deviation at frequencies above 1 KHz. Yet the > > Motorola > > > book calls for setting the deviation to 5 KHz using a 1 KHz > tone. > > > > > > What am I missing here? > > > > > > Army - AE5P > > > Nacogdoches, the oldest town in Texas Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: MSR-2000 Deviation Question
Download the MSR2000 to external controller text from my http://www.radiowrench.com/sonic page. It mentions what I feel is a great/better location for your controller audio connections. cheers skipp > "Army Curtis - AE5P" <[EMAIL PROTECTED]> wrote: > No. The output of the controller goes to the Squelch-Gate card, and > through the several stages of audio amplification there before going > on to the exciter. Since that was the way Motorola designed it, it > seemed like the best way to keep it. > > Cheers, > > Army > > --- In Repeater-Builder@yahoogroups.com, "skipp025" <[EMAIL PROTECTED]> > wrote: > > Your driving the transmitter directly from > > your repeater controller..? ... using the > > back plane method? > > > > Sounds like your repeater controller tx output > > doesn't have enough drive power (capacity) to > > directly drive the tx channel element IDC > > (channel element modulator circuit). > > > > Cheers, > > > > skipp > > www.radiowrench.com > > > > > > > "Army Curtis" <[EMAIL PROTECTED]> wrote: > > > Well gang, I have a real interesting problem for you that's > about to > > > drive me nuts. > > > > > > I have a MSR-2000 repeater that I'm putting into the 2M ham band. > > This > > > is one of the radios removed from service by the Ontario > Provincial > > > Police, so it is a Canadian Motorola VHF low split, originally > > > transmitting at 141.xxx. > > > > > > Following the suggestions on the Repeater-Builder web site, I > have > > > converted it to a ham style controller (CAT-700). The radio tunes > > up per > > > the book, with all meter readings very nominal, and it makes full > > power > > > (100 watts) easily. > > > > > > Here's the issue... it will not deviate the transmitter more than > > about > > > 2.7 KHz using a 1 KHz tone before it starts severely distorting. > The > > > problem appears to be in the exciter, which is a TLD9241A. There > is > > a > > > sticker on the exciter shelf that says 0.260 volts = 5 KHz > > deviation. > > > Anytime I put more than about 0.140 volts into the exciter, it > > starts to > > > distort. I am using an IFR-1200S to send and receive the 1KHz > tone, > > and > > > I'm looking at the wave form of the transmitted signal on the > > 1200S. I > > > have verified the 1200S is clean by looking at its output on > another > > > service monitor, and it is very clean to beyond 6 KHz deviation. > I > > have > > > looked at the audio going into the exciter on a scope, and it is > > very > > > clean to up around 0.400 volts, so I would say that the receiver, > > > controller audio, and transmit audio up to the exciter input is > not > > the > > > problem. > > > > > > I tried changing the exciter to another identical board, same > > problem. I > > > changed the channel element to a known good element, same > problem. I > > > have changed the audio input transistor on the exciter board > (Q501), > > > same problem. I have tried to adjust the IDC on the channel > element. > > > While it does change the deviation, it has no effect on the > > distortion. > > > > > > Here is some additional info I just ran down to the shop to > check. > > > Sending a 5 KHz deviation at 1 KHz signal into the IFR1200S from > > another > > > service monitor shows no distortion, so no problem there. > Putting an > > > audio generator right on the audio input to the exciter shows the > > same > > > issue, but here is where it gets interesting. Changing the audio > > > frequency, I am seeing a definite pre-emphasis network somewhere > in > > the > > > exciter, as a tone of 1 KHz gives about 2.7 KHz deviation, but a > > tone of > > > 3.2 KHz gives right at 5 KHz deviation, with NO distortion. > > > > > > So, here's my question. I always thought you set deviation on an > FM > > > transmitter using a 1 KHz tone, setting a maximum deviation of > > about 4.5 > > > KHz. I can see with this exciter that doing that will result in > much > > > more than 5 KHz deviation at frequencies above 1 KHz. Yet the > > Motorola > > > book calls for setting the deviation to 5 KHz using a 1 KHz > tone. > > > > > > What am I missing here? > > > > > > Army - AE5P > > > Nacogdoches, the oldest town in Texas Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Deviation Limiting/Linearity
Skipp said: Do you use the exact shielded wire I mention in the text..? (from the external controller to the squelch gate module) Are there nearby high powered transmitters? TV or Broadcast Radio? I say: Well, not the exact. But I did use shielded wire and I'm positive there's not a noise problem involved with the controller and audio in/out, PTT and CORworks great. The cable has foil and woven shield and ... if I do say so myself, this repeater sounds great. Good ears too. We have the plug-in preamp. We've got three computers with IRLP, Echolink and WIRES 24/7. Using a CAT250 with the RLS 1000 3-port switch modified slightly to balance the audio between ports.Now, it had a few problems until we restrung the cans and aligned them and made a run of new 214 to the antenna...new one of those too. It has been great since. Just a couple of litle problems. Well, yes..there is Channel 11 south on the Santa Ritas, LOS big time and there's 1330 AM that has spurs EVERYWHERE! We watch that one like a hawk and tattle on them when necessary. They are real close to the repeater. Thanks again. John in Tucson - Original Message - From: "skipp025" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 27, 2004 4:10 PM Subject: [Repeater-Builder] Re: Deviation Limiting/Linearity > "WD7F - John in Tucson" <[EMAIL PROTECTED]> wrote: > It's obvisouly not aligned properly. I can turn it > a tad CCW until the noise increases (possibly going > into oscillation?) and breaks the squelch and then > turn it back a hair CW until it stops. I can see > the audio noise change when I hit the spot where > it goes haywire. The only proper L201 adjustment that I know about is described in the Service Manual, completed with the proper test equipment. I know it reads kind of hard nosed, I'm not trying to be. Now that you've adjusted the coil, you need to align it per the proper instructions. This is such a hard (ie read pain in the arse alignment to complete, that I don't recomend anyone touch L201 unless they know there is a problem. Since you bought your repeater second hand, there is a chance someone else touched the adjustment. > I have listened to this repeater for a few months > with my trusty HTX-202 so I "earballed" it and left > it until we can get to it. We will do the alignment > again according to the manual soon. > > And you said: >: As I describe in my text, above >: 3.5KHz (service monitor) deviated test input, the MSR2000 >: receiver filters start to distort the audio. You can see >: it with a scope at the discriminator output. > > I say: > Yep, you're perzactly right. However, on our second attemp > to set the deviation back in March, we did have it looking > pretty good up to 5K looking at the audio at the input of the > controller. > And it tracked pretty good up to about 3.5K. It held still > for a couple months and then we had the Channel 11 spur > that drove us crazy. It was so strong, I thought the > repeater was broken. One day, there was noise getting through > with the antenna disconnected.. During that episode we > tweaked it again and probably > messed it up. Do you use the exact shielded wire I mention in the text..? (from the external controller to the squelch gate module) Are there nearby high powered transmitters? TV or Broadcast Radio? > Final comment: > Walt, WA4LDS and an engineer at Channel 4 here in Tucson noticed > that when the picture changed on our local Fox channel, the > repeater noise changed. He was instrumental in getting the Channel > 11 engineer to tweak his > transmiter and it is all better now. > Thanks for the response. > de WD7F > John in Tucson Wow, quite the story... You should be able to check the repeater for proper operation into a termination (load). If a gremlin appears when you place the repeater onto the antenna system, you'll probably know where it's comming in. cheers skipp Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: MSR-2000 Deviation Question
No. The output of the controller goes to the Squelch-Gate card, and through the several stages of audio amplification there before going on to the exciter. Since that was the way Motorola designed it, it seemed like the best way to keep it. Cheers, Army --- In Repeater-Builder@yahoogroups.com, "skipp025" <[EMAIL PROTECTED]> wrote: > Your driving the transmitter directly from > your repeater controller..? ... using the > back plane method? > > Sounds like your repeater controller tx output > doesn't have enough drive power (capacity) to > directly drive the tx channel element IDC > (channel element modulator circuit). > > Cheers, > > skipp > www.radiowrench.com > > > > "Army Curtis" <[EMAIL PROTECTED]> wrote: > > Well gang, I have a real interesting problem for you that's about to > > drive me nuts. > > > > I have a MSR-2000 repeater that I'm putting into the 2M ham band. > This > > is one of the radios removed from service by the Ontario Provincial > > Police, so it is a Canadian Motorola VHF low split, originally > > transmitting at 141.xxx. > > > > Following the suggestions on the Repeater-Builder web site, I have > > converted it to a ham style controller (CAT-700). The radio tunes > up per > > the book, with all meter readings very nominal, and it makes full > power > > (100 watts) easily. > > > > Here's the issue... it will not deviate the transmitter more than > about > > 2.7 KHz using a 1 KHz tone before it starts severely distorting. The > > problem appears to be in the exciter, which is a TLD9241A. There is > a > > sticker on the exciter shelf that says 0.260 volts = 5 KHz > deviation. > > Anytime I put more than about 0.140 volts into the exciter, it > starts to > > distort. I am using an IFR-1200S to send and receive the 1KHz tone, > and > > I'm looking at the wave form of the transmitted signal on the > 1200S. I > > have verified the 1200S is clean by looking at its output on another > > service monitor, and it is very clean to beyond 6 KHz deviation. I > have > > looked at the audio going into the exciter on a scope, and it is > very > > clean to up around 0.400 volts, so I would say that the receiver, > > controller audio, and transmit audio up to the exciter input is not > the > > problem. > > > > I tried changing the exciter to another identical board, same > problem. I > > changed the channel element to a known good element, same problem. I > > have changed the audio input transistor on the exciter board (Q501), > > same problem. I have tried to adjust the IDC on the channel element. > > While it does change the deviation, it has no effect on the > distortion. > > > > Here is some additional info I just ran down to the shop to check. > > Sending a 5 KHz deviation at 1 KHz signal into the IFR1200S from > another > > service monitor shows no distortion, so no problem there. Putting an > > audio generator right on the audio input to the exciter shows the > same > > issue, but here is where it gets interesting. Changing the audio > > frequency, I am seeing a definite pre-emphasis network somewhere in > the > > exciter, as a tone of 1 KHz gives about 2.7 KHz deviation, but a > tone of > > 3.2 KHz gives right at 5 KHz deviation, with NO distortion. > > > > So, here's my question. I always thought you set deviation on an FM > > transmitter using a 1 KHz tone, setting a maximum deviation of > about 4.5 > > KHz. I can see with this exciter that doing that will result in much > > more than 5 KHz deviation at frequencies above 1 KHz. Yet the > Motorola > > book calls for setting the deviation to 5 KHz using a 1 KHz tone. > > > > What am I missing here? > > > > Army - AE5P > > Nacogdoches, the oldest town in Texas Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] FYI- Garage Sale 8-21-2004
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[Repeater-Builder] Re: MSR-2000 Deviation Question
Your driving the transmitter directly from your repeater controller..? ... using the back plane method? Sounds like your repeater controller tx output doesn't have enough drive power (capacity) to directly drive the tx channel element IDC (channel element modulator circuit). Cheers, skipp www.radiowrench.com > "Army Curtis" <[EMAIL PROTECTED]> wrote: > Well gang, I have a real interesting problem for you that's about to > drive me nuts. > > I have a MSR-2000 repeater that I'm putting into the 2M ham band. This > is one of the radios removed from service by the Ontario Provincial > Police, so it is a Canadian Motorola VHF low split, originally > transmitting at 141.xxx. > > Following the suggestions on the Repeater-Builder web site, I have > converted it to a ham style controller (CAT-700). The radio tunes up per > the book, with all meter readings very nominal, and it makes full power > (100 watts) easily. > > Here's the issue... it will not deviate the transmitter more than about > 2.7 KHz using a 1 KHz tone before it starts severely distorting. The > problem appears to be in the exciter, which is a TLD9241A. There is a > sticker on the exciter shelf that says 0.260 volts = 5 KHz deviation. > Anytime I put more than about 0.140 volts into the exciter, it starts to > distort. I am using an IFR-1200S to send and receive the 1KHz tone, and > I'm looking at the wave form of the transmitted signal on the 1200S. I > have verified the 1200S is clean by looking at its output on another > service monitor, and it is very clean to beyond 6 KHz deviation. I have > looked at the audio going into the exciter on a scope, and it is very > clean to up around 0.400 volts, so I would say that the receiver, > controller audio, and transmit audio up to the exciter input is not the > problem. > > I tried changing the exciter to another identical board, same problem. I > changed the channel element to a known good element, same problem. I > have changed the audio input transistor on the exciter board (Q501), > same problem. I have tried to adjust the IDC on the channel element. > While it does change the deviation, it has no effect on the distortion. > > Here is some additional info I just ran down to the shop to check. > Sending a 5 KHz deviation at 1 KHz signal into the IFR1200S from another > service monitor shows no distortion, so no problem there. Putting an > audio generator right on the audio input to the exciter shows the same > issue, but here is where it gets interesting. Changing the audio > frequency, I am seeing a definite pre-emphasis network somewhere in the > exciter, as a tone of 1 KHz gives about 2.7 KHz deviation, but a tone of > 3.2 KHz gives right at 5 KHz deviation, with NO distortion. > > So, here's my question. I always thought you set deviation on an FM > transmitter using a 1 KHz tone, setting a maximum deviation of about 4.5 > KHz. I can see with this exciter that doing that will result in much > more than 5 KHz deviation at frequencies above 1 KHz. Yet the Motorola > book calls for setting the deviation to 5 KHz using a 1 KHz tone. > > What am I missing here? > > Army - AE5P > Nacogdoches, the oldest town in Texas Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Deviation Limiting/Linearity
> "WD7F - John in Tucson" <[EMAIL PROTECTED]> wrote: > It's obvisouly not aligned properly. I can turn it > a tad CCW until the noise increases (possibly going > into oscillation?) and breaks the squelch and then > turn it back a hair CW until it stops. I can see > the audio noise change when I hit the spot where > it goes haywire. The only proper L201 adjustment that I know about is described in the Service Manual, completed with the proper test equipment. I know it reads kind of hard nosed, I'm not trying to be. Now that you've adjusted the coil, you need to align it per the proper instructions. This is such a hard (ie read pain in the arse alignment to complete, that I don't recomend anyone touch L201 unless they know there is a problem. Since you bought your repeater second hand, there is a chance someone else touched the adjustment. > I have listened to this repeater for a few months > with my trusty HTX-202 so I "earballed" it and left > it until we can get to it. We will do the alignment > again according to the manual soon. > > And you said: >: As I describe in my text, above >: 3.5KHz (service monitor) deviated test input, the MSR2000 >: receiver filters start to distort the audio. You can see >: it with a scope at the discriminator output. > > I say: > Yep, you're perzactly right. However, on our second attemp > to set the deviation back in March, we did have it looking > pretty good up to 5K looking at the audio at the input of the > controller. > And it tracked pretty good up to about 3.5K. It held still > for a couple months and then we had the Channel 11 spur > that drove us crazy. It was so strong, I thought the > repeater was broken. One day, there was noise getting through > with the antenna disconnected.. During that episode we > tweaked it again and probably > messed it up. Do you use the exact shielded wire I mention in the text..? (from the external controller to the squelch gate module) Are there nearby high powered transmitters? TV or Broadcast Radio? > Final comment: > Walt, WA4LDS and an engineer at Channel 4 here in Tucson noticed > that when the picture changed on our local Fox channel, the > repeater noise changed. He was instrumental in getting the Channel > 11 engineer to tweak his > transmiter and it is all better now. > Thanks for the response. > de WD7F > John in Tucson Wow, quite the story... You should be able to check the repeater for proper operation into a termination (load). If a gremlin appears when you place the repeater onto the antenna system, you'll probably know where it's comming in. cheers skipp Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] MSR-2000 Deviation Question
I'm going to comment on one part of this..the severe distortion. We had the same problem. First of all, I didn't use the voltage stamped on the exciter. It had 0.23 and I think we ended up using 0.19. Then, even though the repeater sounded pretty good, the audio wave form to the controller was severely distorted. It turned out it was the L201 that I was talking about in the deviation linearity problem I have. I finally remembered that I could NOT get the peak called for in the alignment of the limiting circuit. So when I remembered that and tweaked L201 a bit, the audio cleaned up. We then set the IDC and finally I set L201 so that it limited the deviation to approximately 5 K. That ain't by the book as per Skipp. Confession over. As I said to Skipp, I will attempt to do the alignment again...after all, I AM much more experienced now... ;-) de WD7F John in Tucson - Original Message - From: "Army Curtis" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 27, 2004 2:58 PM Subject: [Repeater-Builder] MSR-2000 Deviation Question Well gang, I have a real interesting problem for you that's about to drive me nuts. I have a MSR-2000 repeater that I'm putting into the 2M ham band. This is one of the radios removed from service by the Ontario Provincial Police, so it is a Canadian Motorola VHF low split, originally transmitting at 141.xxx. Following the suggestions on the Repeater-Builder web site, I have converted it to a ham style controller (CAT-700). The radio tunes up per the book, with all meter readings very nominal, and it makes full power (100 watts) easily. Here's the issue... it will not deviate the transmitter more than about 2.7 KHz using a 1 KHz tone before it starts severely distorting. The problem appears to be in the exciter, which is a TLD9241A. There is a sticker on the exciter shelf that says 0.260 volts = 5 KHz deviation. Anytime I put more than about 0.140 volts into the exciter, it starts to distort. I am using an IFR-1200S to send and receive the 1KHz tone, and I'm looking at the wave form of the transmitted signal on the 1200S. I have verified the 1200S is clean by looking at its output on another service monitor, and it is very clean to beyond 6 KHz deviation. I have looked at the audio going into the exciter on a scope, and it is very clean to up around 0.400 volts, so I would say that the receiver, controller audio, and transmit audio up to the exciter input is not the problem. I tried changing the exciter to another identical board, same problem. I changed the channel element to a known good element, same problem. I have changed the audio input transistor on the exciter board (Q501), same problem. I have tried to adjust the IDC on the channel element. While it does change the deviation, it has no effect on the distortion. Here is some additional info I just ran down to the shop to check. Sending a 5 KHz deviation at 1 KHz signal into the IFR1200S from another service monitor shows no distortion, so no problem there. Putting an audio generator right on the audio input to the exciter shows the same issue, but here is where it gets interesting. Changing the audio frequency, I am seeing a definite pre-emphasis network somewhere in the exciter, as a tone of 1 KHz gives about 2.7 KHz deviation, but a tone of 3.2 KHz gives right at 5 KHz deviation, with NO distortion. So, here's my question. I always thought you set deviation on an FM transmitter using a 1 KHz tone, setting a maximum deviation of about 4.5 KHz. I can see with this exciter that doing that will result in much more than 5 KHz deviation at frequencies above 1 KHz. Yet the Motorola book calls for setting the deviation to 5 KHz using a 1 KHz tone. What am I missing here? Army - AE5P Nacogdoches, the oldest town in Texas Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] MSR-2000 Deviation Question
Well gang, I have a real interesting problem for you that's about to drive me nuts. I have a MSR-2000 repeater that I'm putting into the 2M ham band. This is one of the radios removed from service by the Ontario Provincial Police, so it is a Canadian Motorola VHF low split, originally transmitting at 141.xxx. Following the suggestions on the Repeater-Builder web site, I have converted it to a ham style controller (CAT-700). The radio tunes up per the book, with all meter readings very nominal, and it makes full power (100 watts) easily. Here's the issue... it will not deviate the transmitter more than about 2.7 KHz using a 1 KHz tone before it starts severely distorting. The problem appears to be in the exciter, which is a TLD9241A. There is a sticker on the exciter shelf that says 0.260 volts = 5 KHz deviation. Anytime I put more than about 0.140 volts into the exciter, it starts to distort. I am using an IFR-1200S to send and receive the 1KHz tone, and I'm looking at the wave form of the transmitted signal on the 1200S. I have verified the 1200S is clean by looking at its output on another service monitor, and it is very clean to beyond 6 KHz deviation. I have looked at the audio going into the exciter on a scope, and it is very clean to up around 0.400 volts, so I would say that the receiver, controller audio, and transmit audio up to the exciter input is not the problem. I tried changing the exciter to another identical board, same problem. I changed the channel element to a known good element, same problem. I have changed the audio input transistor on the exciter board (Q501), same problem. I have tried to adjust the IDC on the channel element. While it does change the deviation, it has no effect on the distortion. Here is some additional info I just ran down to the shop to check. Sending a 5 KHz deviation at 1 KHz signal into the IFR1200S from another service monitor shows no distortion, so no problem there. Putting an audio generator right on the audio input to the exciter shows the same issue, but here is where it gets interesting. Changing the audio frequency, I am seeing a definite pre-emphasis network somewhere in the exciter, as a tone of 1 KHz gives about 2.7 KHz deviation, but a tone of 3.2 KHz gives right at 5 KHz deviation, with NO distortion. So, here's my question. I always thought you set deviation on an FM transmitter using a 1 KHz tone, setting a maximum deviation of about 4.5 KHz. I can see with this exciter that doing that will result in much more than 5 KHz deviation at frequencies above 1 KHz. Yet the Motorola book calls for setting the deviation to 5 KHz using a 1 KHz tone. What am I missing here? Army - AE5P Nacogdoches, the oldest town in Texas Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] FS LINK COMMUNICATIONS CONTROLLER PARTS
I have for sale a Link Communications Deluxe board and rack mount case for the RLC Club controller. You can find all the info on this product at www.link-comm.com . This is the add-on deluxe board with rack mount case only. You will need the main Club Controller board. The deluxe upgrade gives you another radio port, 8 output lines, DVR support and remote base capabilities. I upgrade to the new Deluxe II board and do not need this anymore. This would be great for someone that has the Club board and wants to upgrade. Or if you're thinking about buying the club controller and want to save money on the Deluxe board and case. Please e-mail me off the list! [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: ARRL insurance
--- In Repeater-Builder@yahoogroups.com, "georgiaskywarn" <[EMAIL PROTECTED]> wrote: > Curious, > Are there any folks in the group who have this for their repeater? > Our club is thinking about getting this. Does anyone know if not > only does this cover "Repeaters" but also if a club gets ARRL > Affilation and then gets it...that it would cover a "Club > Repeater"? I would like to take your responses to the club since we > have a very wide area of repeater owners here. > > Suggestions and Ideas are welcome, > Thanks! > Robert Robert, Years ago one of my local clubs had the ARRL insurance, but it didn't cover acts of god like lightning. The club did a lot of research and found that our local State Farm Insurance agent could give us a lot better price (almost half) on all of the clubs equipment including all the equipment at the repeater site. Be sure you know what the replacement cost of your equipment would be when you call around. Hope that helps. Mark N9MEA Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] ARRL insurance
Curious, Are there any folks in the group who have this for their repeater? Our club is thinking about getting this. Does anyone know if not only does this cover "Repeaters" but also if a club gets ARRL Affilation and then gets it...that it would cover a "Club Repeater"? I would like to take your responses to the club since we have a very wide area of repeater owners here. Suggestions and Ideas are welcome, Thanks! Robert Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Deviation Limiting/Linearity
Well hell, I accidently sent the previous before I was finished: As I was saying, when I said: > I could see the audio noise waveform change on > the scope at the output of the receiver. I can > easily find the ragged edge so I know it's this > adjustment. And you said: No, it's not... I have to ask: Then what is causing the squelch to break and why did it quit acting up when I tweaked it just a bit? It's obvisouly not aligned properly. I can turn it a tad CCW until the noise increases (possibly going into oscillation?) and breaks the squelch and then turn it back a hair CW until it stops. I can see the audio noise change when I hit the spot where it goes haywire. I have listened to this repeater for a few months with my trusty HTX-202 so I "earballed" it and left it until we can get to it. We will do the alignment again according to the manual soon. And you said: As I describe in my text, above 3.5KHz (service monitor) deviated test input, the MSR2000 receiver filters start to distort the audio. You can see it with a scope at the discriminator output. I say: Yep, you're perzactly right. However, on our second attemp to set the deviation back in March, we did have it looking pretty good up to 5K looking at the audio at the input of the controller. And it tracked pretty good up to about 3.5K. It held still for a couple months and then we had the Channel 11 spur that drove us crazy. It was so strong, I thought the repeater was broken. One day, there was noise getting through with the antenna disconnected.. During that episode we tweaked it again and probably messed it up. Final comment: Walt, WA4LDS and an engineer at Channel 4 here in Tucson noticed that when the picture changed on our local Fox channel, the repeater noise changed. He was instrumental in getting the Channel 11 engineer to tweak his transmiter and it is all better now. Thanks for the response. de WD7F John in Tucson - Original Message - From: "skipp025" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 27, 2004 10:35 AM Subject: [Repeater-Builder] Re: Deviation Limiting/Linearity Hi John, I'm here... > "WD7F - John in Tucson" <[EMAIL PROTECTED]> wrote: > Actually, I have two problems so it might > take two threads. (Long-winded too...no less) > It seems that if the deviation is not linear > when setting up IDC/Repeater Level and the > deviation limiting in the receiver. For the non Motorhead (Motorola) people, IDC is the channel element contained deviation control. The repeater in-out deviation will never be (track) linear on any repeater ever. There are at least three wild cards in your problem list. The first is the receiver bandwidth and any included (if used) de-emphasis circuit. The other wild cards are the transmitter (both the users radio and the repeater transmitter) pre-emphasis circuits. When these values get really wacked out, we run into an unbalanced tone level (dtmf is made from two tones) called twist. A big abuser is excessive or user radio over deviation. Most people don't realize how little audio is actually required for proper dtmf and sub-tone (PL) decoding. There are standards, but most out of the box user radios are set excessively hot. Specific to your MSR-2000 and Cat Controller. Know the receiver IF filters are tight. You will not get a good detected waveform with any voice audio deviated signal above 4KHz (without sub tone). So don't try... The statement just above is much of your problem. You also didn't say how you set the receiver on frequency. John, Again set the repeater up as described in my MSR2000 to external controller text, easily found at http://www.radiowrench.com/sonic Then follow what I write below (after a few more comments). > it has an adverse effect on the DTMF decoding > in the VA3TO interface that I use on Echolink. > IRLP and WIRES decoders work nearly flawlessly > with the same audio. This might tell you about a level and twist problem with at the dtmf decoders. A scope at the controller dtmf decoder chip input will give you the real answer. > I found that the 147 side of the keyboard would > not perform well for a lot of DTMF sources if > the deviation didn't track pretty closely from > 0 to 3 K or so. It's probably more than a deviation tracking problem. > We check it by putting in a 1K tone @ 1K deviation, > 2K deviation and 3K deviation, etc. There seems to > be a couple of schools of thought. Yep... > One, adjust IDC/Repeater level so it tracks 1:1, e.g., > 1=1, 2=2, 3=3, 4=4, etc. Close, but no cigar. You have to know the preformance of your receiver filter. As I describe in my text, above 3.5KHz (service monitor) deviated test input, the MSR2000 receiver filters start to distort the audio. You can see it with a scope at the discriminator output. Everyone setting up a receiver should know how that receiver preforms at X value input deviation. Your target value 1:1 deviation ratio for the the MSR is about 3KHz (set at one locatio
Re: [Repeater-Builder] Re: Deviation Limiting/Linearity
Hey Skipp, thanks for the info. I think we had followed the service manual to align everything, including L201. When I said: - Original Message - From: "skipp025" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 27, 2004 10:35 AM Subject: [Repeater-Builder] Re: Deviation Limiting/Linearity Hi John, I'm here... > "WD7F - John in Tucson" <[EMAIL PROTECTED]> wrote: > Actually, I have two problems so it might > take two threads. (Long-winded too...no less) > It seems that if the deviation is not linear > when setting up IDC/Repeater Level and the > deviation limiting in the receiver. For the non Motorhead (Motorola) people, IDC is the channel element contained deviation control. The repeater in-out deviation will never be (track) linear on any repeater ever. There are at least three wild cards in your problem list. The first is the receiver bandwidth and any included (if used) de-emphasis circuit. The other wild cards are the transmitter (both the users radio and the repeater transmitter) pre-emphasis circuits. When these values get really wacked out, we run into an unbalanced tone level (dtmf is made from two tones) called twist. A big abuser is excessive or user radio over deviation. Most people don't realize how little audio is actually required for proper dtmf and sub-tone (PL) decoding. There are standards, but most out of the box user radios are set excessively hot. Specific to your MSR-2000 and Cat Controller. Know the receiver IF filters are tight. You will not get a good detected waveform with any voice audio deviated signal above 4KHz (without sub tone). So don't try... The statement just above is much of your problem. You also didn't say how you set the receiver on frequency. John, Again set the repeater up as described in my MSR2000 to external controller text, easily found at http://www.radiowrench.com/sonic Then follow what I write below (after a few more comments). > it has an adverse effect on the DTMF decoding > in the VA3TO interface that I use on Echolink. > IRLP and WIRES decoders work nearly flawlessly > with the same audio. This might tell you about a level and twist problem with at the dtmf decoders. A scope at the controller dtmf decoder chip input will give you the real answer. > I found that the 147 side of the keyboard would > not perform well for a lot of DTMF sources if > the deviation didn't track pretty closely from > 0 to 3 K or so. It's probably more than a deviation tracking problem. > We check it by putting in a 1K tone @ 1K deviation, > 2K deviation and 3K deviation, etc. There seems to > be a couple of schools of thought. Yep... > One, adjust IDC/Repeater level so it tracks 1:1, e.g., > 1=1, 2=2, 3=3, 4=4, etc. Close, but no cigar. You have to know the preformance of your receiver filter. As I describe in my text, above 3.5KHz (service monitor) deviated test input, the MSR2000 receiver filters start to distort the audio. You can see it with a scope at the discriminator output. Everyone setting up a receiver should know how that receiver preforms at X value input deviation. Your target value 1:1 deviation ratio for the the MSR is about 3KHz (set at one location) only, depending on the preformance of your receiver and how your external controller processes the audio. Be sure to "pull the TX PL tone reed" when checking these values. The 3KHz value is relative and "season to taste" based on your observations of the receiver to transmitter through-put (with no PL). I have seen and used values of 3.5 and up to 4KHz because some receivers filters were fairly linear at those test signal input - deviation levels. The key is to know the receiver preformance first, easily measure with a service monitor. You must also keep in mind that your repeater controller might not provide flat in-out audio. > The other is to check the deviation with no input > and adjust the deviation to compensate for noise > in the exciter, e.g., 1=1.2, 2=2.2, 3=3.2, etc. Yuck... > We have done it both ways. It's seems pretty tough > to get the linearity AND the deviation limiter in > the receiver aligned so that the deviaton is linear > and limited to about 5K and see a nice undistorted > audio waveform. As you describe both methods above, you will never see what you are trying to adjust for. You are shooting yourself in the foot. > we began to have what appeared to be an intermod or > spur problem which would break squelch and key the > repeater. > I put my adjusting tool on the L201 deviation > limiting adjustment in the receiver and cracked > it a little CW (higher deviation allowed) and > the problem went away. I bit my tongue when you wrote that you touched L201, you now need to follow the service manual instructions on how to get it back to where it should be. Before anything else, you now need to follow the Service Manual information to reset L201, second would then be to set the channel element to the best center frequency. I use a service monitor, set to y
Re: [Repeater-Builder] 1.2 ghz repeater
There are many 1.2 repeaters in Northern California that are comprised of a pair of TM-541's. Several of the systems are linked and get alot of activity with no failures. The Mitsubishi power brick in the 541's is rated at ~18 watts. From the factory the high power setting is 10 watts, so it is some what de-rated to start with. I've just added two small fans to the heat sink and my repeater has been going strong with the original radios since 1995. Here are a few pics of a TM-241 showing the COS connection point, it's the same in all the x41 and x31 radios. http://www.fitzharris.com/~fitz/x41/ For duplexers check out Angle Linear and Telewave. I'm using Wacom, but we all know they are gone. -Sean On Tue, 27 Jul 2004, Russ wrote: > I see that icom makes the D-star didi/ana repeater but i have not heard > results , and as far as mobles being used , well the local 2 meter > repeater here in canton is a pair of 1971 icom -28A radios modded out > hooked to Scomm7K controller , 31 yrs and still strong at 30 watts , > not to mention 4 different antennii and 2 changes of Feedline , > Lightning is not kind in my area esp when the 200' tower is on one of > the highest hills around . > > I was thinking of going the kenwood tm541 direction my self but the > only problem is where to tap the COR/COS point , and after that what > kind of duplexer or notch filter would u use at that freq , i know > comet makes a nice 14.1 dbi base/repeater for around $150 , and we > have enuf hardline to send it upa 100' tower , just not sure of the > actual radios and controller yet and all the interfacing of it > > Russ > N3TIH > > - Original Message - > From: "Jack White" <[EMAIL PROTECTED]> > To: > Sent: Monday, July 26, 2004 7:46 PM > Subject: RE: [Repeater-Builder] 1.2 ghz repeater > > > > Russ, > > I have been looking for the same information myself. Haven't found much > yet > > other than the Icom D-Star someone mentioned. They are supposed to work > > digital and analog! I have heard of a few installations where guys are > > running 2 Kenwood 541s back to back with some minor mods. I don't usually > > recommend using ham mobiles for repeater duty but they will work in a > pinch. > > The main problem using mobiles is that the power amps are designed for > > intermittent duty, not 100% duty as needed for repeater operation. > Switching > > to low power and using a fan can help. Sometimes ham mobile transmitters > > have spurious emissions that hinder repeater operation. A repeater > > transmitter needs to be clean. Check the Kenwood specs. Maybe they're ok. > > If you find any More information that helps, I'd love to hear about it. > > > > Good Luck, > > J. White > > WA2RZG > > > > -Original Message- > > From: Russ [mailto:[EMAIL PROTECTED] > > Sent: Monday, July 26, 2004 12:03 PM > > To: Repeater-Builder@yahoogroups.com > > Subject: [Repeater-Builder] 1.2 ghz repeater > > > > who makes 1.2 ghz equipment for repeater usage , im drawing a blank > and > > web searches arnt proving helpful either ... > > > > Russ > > N3TIH > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Duplexer...on eBay
At 08:23 AM 7/27/04, "Ron Stordahl N5IN" <[EMAIL PROTECTED]> wrote: >Here are some links...but if previous experience is any guide these >links do not always get thru unbroken in posts like these. There is a trick you can do to prevent "broken" URLS - just bracket them with < and > characters. It's part of the URL specification - RFC 1738 . Here's the link unbroken: Mike WA6ILQ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Deviation Limiting/Linearity
Hi John, I'm here... > "WD7F - John in Tucson" <[EMAIL PROTECTED]> wrote: > Actually, I have two problems so it might > take two threads. (Long-winded too...no less) > It seems that if the deviation is not linear > when setting up IDC/Repeater Level and the > deviation limiting in the receiver. For the non Motorhead (Motorola) people, IDC is the channel element contained deviation control. The repeater in-out deviation will never be (track) linear on any repeater ever. There are at least three wild cards in your problem list. The first is the receiver bandwidth and any included (if used) de-emphasis circuit. The other wild cards are the transmitter (both the users radio and the repeater transmitter) pre-emphasis circuits. When these values get really wacked out, we run into an unbalanced tone level (dtmf is made from two tones) called twist. A big abuser is excessive or user radio over deviation. Most people don't realize how little audio is actually required for proper dtmf and sub-tone (PL) decoding. There are standards, but most out of the box user radios are set excessively hot. Specific to your MSR-2000 and Cat Controller. Know the receiver IF filters are tight. You will not get a good detected waveform with any voice audio deviated signal above 4KHz (without sub tone). So don't try... The statement just above is much of your problem. You also didn't say how you set the receiver on frequency. John, Again set the repeater up as described in my MSR2000 to external controller text, easily found at http://www.radiowrench.com/sonic Then follow what I write below (after a few more comments). > it has an adverse effect on the DTMF decoding > in the VA3TO interface that I use on Echolink. > IRLP and WIRES decoders work nearly flawlessly > with the same audio. This might tell you about a level and twist problem with at the dtmf decoders. A scope at the controller dtmf decoder chip input will give you the real answer. > I found that the 147 side of the keyboard would > not perform well for a lot of DTMF sources if > the deviation didn't track pretty closely from > 0 to 3 K or so. It's probably more than a deviation tracking problem. > We check it by putting in a 1K tone @ 1K deviation, > 2K deviation and 3K deviation, etc. There seems to > be a couple of schools of thought. Yep... > One, adjust IDC/Repeater level so it tracks 1:1, e.g., > 1=1, 2=2, 3=3, 4=4, etc. Close, but no cigar. You have to know the preformance of your receiver filter. As I describe in my text, above 3.5KHz (service monitor) deviated test input, the MSR2000 receiver filters start to distort the audio. You can see it with a scope at the discriminator output. Everyone setting up a receiver should know how that receiver preforms at X value input deviation. Your target value 1:1 deviation ratio for the the MSR is about 3KHz (set at one location) only, depending on the preformance of your receiver and how your external controller processes the audio. Be sure to "pull the TX PL tone reed" when checking these values. The 3KHz value is relative and "season to taste" based on your observations of the receiver to transmitter through-put (with no PL). I have seen and used values of 3.5 and up to 4KHz because some receivers filters were fairly linear at those test signal input - deviation levels. The key is to know the receiver preformance first, easily measure with a service monitor. You must also keep in mind that your repeater controller might not provide flat in-out audio. > The other is to check the deviation with no input > and adjust the deviation to compensate for noise > in the exciter, e.g., 1=1.2, 2=2.2, 3=3.2, etc. Yuck... > We have done it both ways. It's seems pretty tough > to get the linearity AND the deviation limiter in > the receiver aligned so that the deviaton is linear > and limited to about 5K and see a nice undistorted > audio waveform. As you describe both methods above, you will never see what you are trying to adjust for. You are shooting yourself in the foot. > we began to have what appeared to be an intermod or > spur problem which would break squelch and key the > repeater. > I put my adjusting tool on the L201 deviation > limiting adjustment in the receiver and cracked > it a little CW (higher deviation allowed) and > the problem went away. I bit my tongue when you wrote that you touched L201, you now need to follow the service manual instructions on how to get it back to where it should be. Before anything else, you now need to follow the Service Manual information to reset L201, second would then be to set the channel element to the best center frequency. I use a service monitor, set to you frequency minus the 10.7 (in most receivers) IF. If your receiver alignment is good, you then test and note (on paper), the discriminator audio output for various test tone input (deviated) lev
[Repeater-Builder] Re: Receiver Sensitivity Testing Through Duplexer
Mathew, Four miles range from a handheld is not that bad with an antenna at 60 feet. Then consider the almost 20 db power advantage that your transmitter has over the user's handheld, about 3 1/2 S units. You didn't mention the band you are using or your antenna type, what kind of receiver, transmitter, terrain, etc. These are going to affect what you should expect out of your system. "...their signal is not really that bad." Could be many things; off freq, too little PL, too much PL, over deviation, not enough hi-pass filtering in their HT transmitter, rpt receiver bandpass very narrow. Put a scope on your rpt disciminator for clues. Also, look at receiver limiting and see if it changes during modulation. Could be an IF alignment issue. FWIW, an isotee can be constucted in about five minutes from a UHF tee. Unscrew the male pin, push out the female section, saw off one end of the female section leaving the threaded portion intact, and reassemble. Then mark the end with no center conductor with red paint, magic marker or something, to designate the isolated end. (Not marking the isoport will eventually cause you grief!) Plug your Cushman into the isolated port and expect 20 to 30 db loss though the port, depending on your frequency. You can leave the isotee in line permanently for testing, sytem reformance, degradation over time, etc. 73, Al, K9SI >Date: Tue, 27 Jul 2004 00:01:58 - >From: "w9mwq" <[EMAIL PROTECTED]> > Subject: Receiver Sensitivity Testing Through Duplexer > > I need a little advise here. I want to test my repeater's > sensitivity through the duplexer's while the transmitter is keyed > up, into my Cushman Service Monitor. What is the best method of > doing this? Do I need an isolator of some sort, or will the service > monitor handle both the incoming power and the outgoing signal > generator? It's a Cushman 6030 by the way. The repeater is working > excellent for the most part. The problem that I am having is on > weak signals, the audio is being chopped out, almost like the PL > deck is shutting down. On the bench, the receiver is at about .25 > microvolts sensitivity at 12 DB Sinad. Audio out of the transmitter > is about 4KHz wide, and clean at 100 watts. Any suggestions. > Handhelds are able to get in from about 4 miles away, mobiles have > no troubles at 30 miles away. The antenna is only up at 60' right > now, fed with 120' of 7/8" Andrews hardline. But it seems the > handhelds are the one's having the problems, and their signal is not > really that bad. Help please. > > Mathew Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Dubus VHF PHEMPT GaAs Fet Preamp Article now available on sonic
Hello GaAs "Gas Fet" Preamplifier People... Now set up to rock and roll (download) from my sonic web page, an excellent Dubus Magazine Article about building a VHF PHEMPT Preamplifier (preamp). The PHEMPT is a "newer" generation Fet, which has excellent 3rd order intercept preformance. Also my plug for Dubus Magazine is included on the Description page. http://www.radiowrench.com/sonic About half way down the columb (list). If you want the low down on PHEMPT Preamps, this article will get you well on your way. Also added is my "poor mans PL (sub-tone) encoder. Enjoy skipp [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Deviation Limiting/Linearity
Actually, I have two problems so it might take two threads. (Long-winded too...no less) Repeater: MSR2000 Controller: CAT250 interfaced via Squelch Gate card. I have been chasing my tail on two issues. One is deviation limiting and the other is deviation linearity. It seems that if the deviation is not linear when setting up IDC/Repeater Level and the deviation limiting in the receiver, if has an adverse effect on the DTMF decoding in the VA3TO interface that I use on Echolink. IRLP and WIRES decoders work nearly flawlessly with the same audio. I found that the 147 side of the keyboard would not perform well for a lot of DTMF sources if the deviation didn't track pretty closely from 0 to 3 K or so. We check it by putting in a 1K tone @ 1K deviation, 2K deviation and 3K deviation, etc. There seems to be a couple of schools of thought. One, adjust IDC/Repeater level so it tracks 1:1, e.g., 1=1, 2=2, 3=3, 4=4, etc. The other is to check the deviation with no input and adjust the deviation to compensate for noise in the exciter, e.g., 1=1.2, 2=2.2, 3=3.2, etc. We have done it both ways. It's seems pretty tough to get the linearity AND the deviation limiter in the receiver aligned so that the deviaton is linear and limited to about 5K and see a nice undistorted audio waveform. After we had done an alignment and was fairly satisfied with the results, a month or so later, we began to have what appeared to be an intermod or spur problem which would break squelch and key the repeater. We thought SURE it was a noisy rig somewhere or the TV Channel 11 spur we found a few months ago. We chased it around several days. We re-soldered suspected back plane pins on the R1 Audio and though we fixed it. Then it comes back again. Changed out the R1 Audio card and it worked for a day or two, and it's back again! Thought it was the Squelch Gate card and checked every solder joint a few times. Used a scope to look at everything. This morning at about 4 AM, I put my adjusting tool on the L201 deviation limiting adjustment in the receiver and cracked it a little CW (higher deviation allowed) and the problem went away. I could see the audio noise waveform change on the scope at the output of the receiver. I can easily find the ragged edge so I know it's this adjustment. I even put the suspected R1 Audio card back in and it works good. However, 147 won't work on K7IOUs Kenwood (again) nowbecause the deviation is no longer linear. By the way, the repeater still sounds great even if the deviaton is not linear...so long as the limiter is working. Can any of you "gurus" with lots of experience give me a hint on the alignment? Or should I throw away the VA3TO interface? Skipp, I have read your alignment procedure a hundred times, and it makes sense on paper, but I'm not confident that I'm doing it right. I would think that the deviation limiting would not have an effect on the linearity, but it seems that it does. de WD7F John in Tucson Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Repeater-Builder] Re: Fw: How to modify DB 212 for 6 meters
here are two pages I found on the db-212 conversion http://www.ccdx.org/zedyx/mods/db212.htm http://users3.ev1.net/~xanaduu/db201/ --- In Repeater-Builder@yahoogroups.com, "russ" <[EMAIL PROTECTED]> wrote: > You mite want to ask the same folks who came up with the mod listed below. > > - Original Message - > From: "Michael J.Talkington" <[EMAIL PROTECTED]> > To: > Sent: Tuesday, July 27, 2004 10:04 AM > Subject: [Repeater-Builder] Re: Fw: How to modify DB 212 for 6 meters > > > > > > I want to know how to make the harness for two of these.Also would > > like to find out how to make one for four of the db-212 cut for six > > meters.What are the formulas thanks Mike KC8FWD > > > > > > --- In Repeater-Builder@yahoogroups.com, "John J. Riddell" > > <[EMAIL PROTECTED]> wrote: > > > The following was received after a request to Cook Towers about > > retuning a DB-212 antenna that i have which > > > is presently on 42 Mhz. > > > > > > John VE3AMZ Waterloo Ontario. > > > > > > > > > - Original Message - > > > From: [EMAIL PROTECTED] > > > > > > Sent: Tuesday, July 27, 2004 9:42 AM > > > Subject: How to modify DB 212 for 6 meters > > > > > > > > > Six meter mod for the DB-212 > > > Real gain for six meters (DBd) > > > > > > > > > For the DB-212, you would just measure the current length of the > > dipole and > > > then multiply this length by (current_freq/new-freq). So if the > > current > > > length is 180" and the current freq is 50 and you want to go to > > 53.5 MHz. > > > The new length is 180*(50/53.5) in inches. > > > > > > To change the length you will need to remove the pop-rivet and a > > little > > > dimple that the tuner uses to hold the trombone in place until > > production > > > can install the rivet. > > > > > > Sometimes the vswr depends on the tower face. If you want to super > > tune the > > > antenna, do the following. Set the antenna up on a tower leg a few > > feet off > > > the ground. Then free the trombone, put it at the length you want. > > Next > > > check the refected. Then get some long stick and start moving the > > trombone > > > while watching the refelcted. When you get the best possible vswr, > > redo the > > > rivets. > > > > > > This has been tested here in our shop > > > and it works well! > > > > > > Cook Towers, INC. > > > Toll Free (877)992-2665 > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Duplexer...on eBay
Its a Fiplex duplexer. We sell them as well and have had some very good luck with them on the ham bands. -Original Message- From: Ron Stordahl N5IN [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 27, 2004 11:23 To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Duplexer...on eBay I noticed a 2 meter duplexer on eBay which looks promising on the surface. I sent an e-mail to the seller, using the eBay mail system which does not reveal his actual address, but so far (24 hours) no response. My interest is in a more complex device to support 144.39 simplex plus 146.850TX 146.250RX voice repeater to the same antenna, and that was the subject of my e-mail. Here are some links...but if previous experience is any guide these links do not always get thru unbroken in posts like these. So if they don't, try searching for "2 meters ready" (yes that is "meters") that should do it. The seller has a store "SUNPCS" if that is any clue. Links http://stores.ebay.com/SUNPCS_W0QQsspagenameZl2QQtZkm http://cgi.ebay.com/ws/eBayISAPI.dll? ViewItem&category=1502&item=5711311161&tc=photo So my question...anyone have any idea who the manufacturer of the duplexer? One thing I notice as that the interconnects between the cans is done with uninsulated solid outer conductor (probably aluminum) coax. Ron Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Duplexer...on eBay
I noticed a 2 meter duplexer on eBay which looks promising on the surface. I sent an e-mail to the seller, using the eBay mail system which does not reveal his actual address, but so far (24 hours) no response. My interest is in a more complex device to support 144.39 simplex plus 146.850TX 146.250RX voice repeater to the same antenna, and that was the subject of my e-mail. Here are some links...but if previous experience is any guide these links do not always get thru unbroken in posts like these. So if they don't, try searching for "2 meters ready" (yes that is "meters") that should do it. The seller has a store "SUNPCS" if that is any clue. Links http://stores.ebay.com/SUNPCS_W0QQsspagenameZl2QQtZkm http://cgi.ebay.com/ws/eBayISAPI.dll? ViewItem&category=1502&item=5711311161&tc=photo So my question...anyone have any idea who the manufacturer of the duplexer? One thing I notice as that the interconnects between the cans is done with uninsulated solid outer conductor (probably aluminum) coax. Ron Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Fw: How to modify DB 212 for 6 meters
You mite want to ask the same folks who came up with the mod listed below. - Original Message - From: "Michael J.Talkington" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 27, 2004 10:04 AM Subject: [Repeater-Builder] Re: Fw: How to modify DB 212 for 6 meters > > I want to know how to make the harness for two of these.Also would > like to find out how to make one for four of the db-212 cut for six > meters.What are the formulas thanks Mike KC8FWD > > > --- In Repeater-Builder@yahoogroups.com, "John J. Riddell" > <[EMAIL PROTECTED]> wrote: > > The following was received after a request to Cook Towers about > retuning a DB-212 antenna that i have which > > is presently on 42 Mhz. > > > > John VE3AMZ Waterloo Ontario. > > > > > > - Original Message - > > From: [EMAIL PROTECTED] > > > > Sent: Tuesday, July 27, 2004 9:42 AM > > Subject: How to modify DB 212 for 6 meters > > > > > > Six meter mod for the DB-212 > > Real gain for six meters (DBd) > > > > > > For the DB-212, you would just measure the current length of the > dipole and > > then multiply this length by (current_freq/new-freq). So if the > current > > length is 180" and the current freq is 50 and you want to go to > 53.5 MHz. > > The new length is 180*(50/53.5) in inches. > > > > To change the length you will need to remove the pop-rivet and a > little > > dimple that the tuner uses to hold the trombone in place until > production > > can install the rivet. > > > > Sometimes the vswr depends on the tower face. If you want to super > tune the > > antenna, do the following. Set the antenna up on a tower leg a few > feet off > > the ground. Then free the trombone, put it at the length you want. > Next > > check the refected. Then get some long stick and start moving the > trombone > > while watching the refelcted. When you get the best possible vswr, > redo the > > rivets. > > > > This has been tested here in our shop > > and it works well! > > > > Cook Towers, INC. > > Toll Free (877)992-2665 > > > > > > > Yahoo! Groups Links > > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] 1.2 ghz repeater
I see that icom makes the D-star didi/ana repeater but i have not heard results , and as far as mobles being used , well the local 2 meter repeater here in canton is a pair of 1971 icom -28A radios modded out hooked to Scomm7K controller , 31 yrs and still strong at 30 watts , not to mention 4 different antennii and 2 changes of Feedline , Lightning is not kind in my area esp when the 200' tower is on one of the highest hills around . I was thinking of going the kenwood tm541 direction my self but the only problem is where to tap the COR/COS point , and after that what kind of duplexer or notch filter would u use at that freq , i know comet makes a nice 14.1 dbi base/repeater for around $150 , and we have enuf hardline to send it upa 100' tower , just not sure of the actual radios and controller yet and all the interfacing of it Russ N3TIH - Original Message - From: "Jack White" <[EMAIL PROTECTED]> To: Sent: Monday, July 26, 2004 7:46 PM Subject: RE: [Repeater-Builder] 1.2 ghz repeater > Russ, > I have been looking for the same information myself. Haven't found much yet > other than the Icom D-Star someone mentioned. They are supposed to work > digital and analog! I have heard of a few installations where guys are > running 2 Kenwood 541s back to back with some minor mods. I don't usually > recommend using ham mobiles for repeater duty but they will work in a pinch. > The main problem using mobiles is that the power amps are designed for > intermittent duty, not 100% duty as needed for repeater operation. Switching > to low power and using a fan can help. Sometimes ham mobile transmitters > have spurious emissions that hinder repeater operation. A repeater > transmitter needs to be clean. Check the Kenwood specs. Maybe they're ok. > If you find any More information that helps, I'd love to hear about it. > > Good Luck, > J. White > WA2RZG > > -Original Message- > From: Russ [mailto:[EMAIL PROTECTED] > Sent: Monday, July 26, 2004 12:03 PM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] 1.2 ghz repeater > > who makes 1.2 ghz equipment for repeater usage , im drawing a blank and > web searches arnt proving helpful either ... > > Russ > N3TIH > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > Yahoo! Groups Links > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] 1.2 ghz repeater
Russ, I have been looking for the same information myself. Haven't found much yet other than the Icom D-Star someone mentioned. They are supposed to work digital and analog! I have heard of a few installations where guys are running 2 Kenwood 541s back to back with some minor mods. I don't usually recommend using ham mobiles for repeater duty but they will work in a pinch. The main problem using mobiles is that the power amps are designed for intermittent duty, not 100% duty as needed for repeater operation. Switching to low power and using a fan can help. Sometimes ham mobile transmitters have spurious emissions that hinder repeater operation. A repeater transmitter needs to be clean. Check the Kenwood specs. Maybe they're ok. If you find any More information that helps, I'd love to hear about it. Good Luck, J. White WA2RZG -Original Message- From: Russ [mailto:[EMAIL PROTECTED] Sent: Monday, July 26, 2004 12:03 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] 1.2 ghz repeater who makes 1.2 ghz equipment for repeater usage , im drawing a blank and web searches arnt proving helpful either ... Russ N3TIH Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Fw: How to modify DB 212 for 6 meters
I want to know how to make the harness for two of these.Also would like to find out how to make one for four of the db-212 cut for six meters.What are the formulas thanks Mike KC8FWD --- In Repeater-Builder@yahoogroups.com, "John J. Riddell" <[EMAIL PROTECTED]> wrote: > The following was received after a request to Cook Towers about retuning a DB-212 antenna that i have which > is presently on 42 Mhz. > > John VE3AMZ Waterloo Ontario. > > > - Original Message - > From: [EMAIL PROTECTED] > > Sent: Tuesday, July 27, 2004 9:42 AM > Subject: How to modify DB 212 for 6 meters > > > Six meter mod for the DB-212 > Real gain for six meters (DBd) > > > For the DB-212, you would just measure the current length of the dipole and > then multiply this length by (current_freq/new-freq). So if the current > length is 180" and the current freq is 50 and you want to go to 53.5 MHz. > The new length is 180*(50/53.5) in inches. > > To change the length you will need to remove the pop-rivet and a little > dimple that the tuner uses to hold the trombone in place until production > can install the rivet. > > Sometimes the vswr depends on the tower face. If you want to super tune the > antenna, do the following. Set the antenna up on a tower leg a few feet off > the ground. Then free the trombone, put it at the length you want. Next > check the refected. Then get some long stick and start moving the trombone > while watching the refelcted. When you get the best possible vswr, redo the > rivets. > > This has been tested here in our shop > and it works well! > > Cook Towers, INC. > Toll Free (877)992-2665 Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Fw: How to modify DB 212 for 6 meters
The following was received after a request to Cook Towers about retuning a DB-212 antenna that i have which is presently on 42 Mhz. John VE3AMZ Waterloo Ontario. - Original Message - From: [EMAIL PROTECTED] Sent: Tuesday, July 27, 2004 9:42 AM Subject: How to modify DB 212 for 6 meters Six meter mod for the DB-212Real gain for six meters (DBd)For the DB-212, you would just measure the current length of the dipole andthen multiply this length by (current_freq/new-freq). So if the currentlength is 180" and the current freq is 50 and you want to go to 53.5 MHz.The new length is 180*(50/53.5) in inches.To change the length you will need to remove the pop-rivet and a littledimple that the tuner uses to hold the trombone in place until productioncan install the rivet.Sometimes the vswr depends on the tower face. If you want to super tune theantenna, do the following. Set the antenna up on a tower leg a few feet offthe ground. Then free the trombone, put it at the length you want. Nextcheck the refected. Then get some long stick and start moving the trombonewhile watching the refelcted. When you get the best possible vswr, redo therivets.This has been tested here in our shopand it works well!Cook Towers, INC.Toll Free (877)992-2665 Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] 1.2 ghz repeater
Try 902 MHz, lots of commercial gear available at much less cost. Check out the Yahoo group AR902MHZ. 73, Dick, W1KSZ 902.1375/927.1375 131.8 PL -Original Message- From: Russ <[EMAIL PROTECTED]> Sent: Jul 26, 2004 12:02 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] 1.2 ghz repeater who makes 1.2 ghz equipment for repeater usage , im drawing a blank and web searches arnt proving helpful either ... Russ N3TIH Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Mike WA6ILQ wrote: > I like the idea but I'd use a parked mobile instead. HT's are hand held > and can > be moved which will change the signal level, plus they pull 3/4 to 1amp from > the batteries and can suck them down, which also changes the signal level. > The use of a parked mobile - set to the lowest power level it can do - > eliminates > both factors from the equation. > > Mike WA6ILQ > I use my Kenwood G-71 at what they call 'extra-low' power-about 60-75mW, with no antenna. At that power level, reflected power isn't likely to do much damage, since there's probably that much or more with the duck on high power. But yes, you do have a problem with movement with a handheld. -- Jim Barbour WD8CHL Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Bag Cell Phone interface?
I have a Motorola S1801A Cellular Data-Passage unit that was made for interfacing a computer to a bag phone, I'm not sure if it passes dial tone and voice, it's for sale if you can use it. $10 including shipping. 73, Joe, k1ike All outgoing email scanned with Norton AntiVirus2004. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
RE: [Repeater-Builder] Bag Cell Phone rant?
So THAT'S why my signal sounds like crap, I'm not running it through a "muldem".;>) 73, Kenneth Buley Bullitt County ARES/RACES Coordinator KE4AWY Bullitt County EMA CD-2 Bullitt County Red Cross Disaster Communications BC-6 -Original Message- From: Steve Grantham [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 27, 2004 1:12 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Bag Cell Phone rant? Don't forget that this "digital" radio stuff is only digital in the muldem. 73, Steve, AA5SG Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Bag Cell Phone interface?
On Jul 26, 2004, at 3:26 PM, Steve Smith wrote: > Doesn't Verizon have the On Star contract with GM and accordingly has > to maintain analog? Don't you mean BlondeStar? ;-) http://www.smartelic.com/ - click on the BlondeStar logos. Very funny stuff. -- Nate Duehr, [EMAIL PROTECTED] - WY0X Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Bag Cell Phone rant?
Don't forget that this "digital" radio stuff is only digital in the muldem. The RF is still analog, and good linearity is required to have a good BER and more effective communications. Deep huh? The only reason I bring this up is for humor value. I once asked a manufacturer's representative about maximizing linearity in their PAs, and his response was, "It's all digital". I just laughed, and he just looked puzzled. 73, Steve, AA5SG - Original Message - From: "Tony King - W4ZT" <[EMAIL PROTECTED]> To: Sent: Monday, July 26, 2004 4:41 PM Subject: Re: [Repeater-Builder] Bag Cell Phone rant? > At 05:19 PM 7/26/2004, you wrote: > > > >Definition of Analog > > > >8 Track Tapes > >Cassette - dang near > >Steel Cars > > > >How Times have changed > > Mathew, you forgot one! The HUMAN BEING... we're all analog... so no > matter how many digital systems are out there, they all have to come back > to analog to interface with US makes me laugh to see how badly they're > doing with that. 73, Tony W4ZT > > > > > > > Yahoo! Groups Links > > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Will give that a try tomorrow and see if it is the same and take it from there. I'm almost betting it is the Handhelds with the elevated pl tone output. Going to have to give another stab at making an iso tee to work with. Thanks for the input. Will let you know how it comes out. Mathew > You want the user to be a bit noisy when you do that test. If you then turn > your repeater TX on and nothing changes, you don't have desense. > > Chuck > WB2EDV > > > > - Original Message - > From: "Mathew Quaife" <[EMAIL PROTECTED]> > To: > Sent: Monday, July 26, 2004 10:48 PM > Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through > Duplexer > > > > That I can do, I have another antenna that is up that I can hook to the > SM. > > From what I can tell I am not getting any desence, as I did have one > > operator about 25 miles away, listening through the receiver ouput, I > could > > here him just fine and that was with the repeat mode turned off. He would > > talk, and I would key up the transmitter, nothing would change. I'm > leading > > it back to the PL area, as was mentioned, I think it is killing the PL as > > they talk. I just want to make sure the duplexer is tuned up properly and > > all is working there. If its the PL, and is coming from the handie > talkie, > > not much I can do there. > > > > > > > Mathew, > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
You want the user to be a bit noisy when you do that test. If you then turn your repeater TX on and nothing changes, you don't have desense. Chuck WB2EDV - Original Message - From: "Mathew Quaife" <[EMAIL PROTECTED]> To: Sent: Monday, July 26, 2004 10:48 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > That I can do, I have another antenna that is up that I can hook to the SM. > From what I can tell I am not getting any desence, as I did have one > operator about 25 miles away, listening through the receiver ouput, I could > here him just fine and that was with the repeat mode turned off. He would > talk, and I would key up the transmitter, nothing would change. I'm leading > it back to the PL area, as was mentioned, I think it is killing the PL as > they talk. I just want to make sure the duplexer is tuned up properly and > all is working there. If its the PL, and is coming from the handie talkie, > not much I can do there. > > > > Mathew, > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
That I can do, I have another antenna that is up that I can hook to the SM. >From what I can tell I am not getting any desence, as I did have one operator about 25 miles away, listening through the receiver ouput, I could here him just fine and that was with the repeat mode turned off. He would talk, and I would key up the transmitter, nothing would change. I'm leading it back to the PL area, as was mentioned, I think it is killing the PL as they talk. I just want to make sure the duplexer is tuned up properly and all is working there. If its the PL, and is coming from the handie talkie, not much I can do there. > Mathew, > > No, you should not disturb any of the hookups between your duplexer and > antenna, transmitter, or receiver. What I meant by a "separate antenna" > is one connected to the output of your service monitor, and which > radiates a signal that is picked up by your repeater antenna. > > This method will prove or disprove whether desense is caused by your own > transmitter. It will also enable you to determine if desense is being > caused by a nearby transmitter on a different frequency, if the SINAD > reading suddenly drops while your repeater transmitter is disabled. If > this happens, you can use a spectrum analyzer to sweep the band several > MHz each side of your receiver frequency and note what carriers are > present at the same time your SINAD drops. As I noted in a previous > posting, a bandpass filter may be needed to eliminate desense caused by > a nearby transmitter. > > 73, Eric Lemmon WB6FLY > > Mathew Quaife wrote: > > > > Could I get by using a separate antenna to test for desense? Say leaving > > the antenna for the receiver through the duplexer and hooking the > > transmitter up to another antenna, would that work the same to test for > > desense. I tried to make an iso-tee, did not have real good luck with it, > > but then as far as a machinist, I have no luck at that, hihi > > > > > > Yahoo! Groups Links > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Actually the repeater is here at my home qth, only other transmitter is a 460 commercial repeater about 2 miles away, do don't think I am getting any problems from that one. Mathew - Original Message - From: "Mike WA6ILQ" <[EMAIL PROTECTED]> To: Sent: Monday, July 26, 2004 7:33 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > Forgot to mention one thing - you don't even need to visit the site > if the repeater has an autopatch (or even a remote base that is on > a different band) you can listen to the RX via the patch or remote > and let the main channel TX time out. If the quieting level in the > RX goes up exactly when the TX drops off that indicates a problem. > > Mike WA6ILQ > > At 07:14 PM 7/26/04, you wrote: > > >I like the idea but I'd use a parked mobile instead. HT's are hand held > >and can > >be moved which will change the signal level, plus they pull 3/4 to 1amp from > >the batteries and can suck them down, which also changes the signal level. > >The use of a parked mobile - set to the lowest power level it can do - > >eliminates > >both factors from the equation. > > > >Mike WA6ILQ > > > >At 06:57 PM 7/26/04, you wrote: > > > > >Here's one simple test. Have someone with an HT get into a noisy location, > > >then disable your repeater transmitter while listening on the local speaker. > > >If all of a sudden the HT becomes full quieting, you've got a desense > > >problem. > > > > > >Chuck > > >WB2EDV > > > > > > > > > > > >- Original Message - > > >From: "w9mwq" <[EMAIL PROTECTED]> > > >To: > > >Sent: Monday, July 26, 2004 8:01 PM > > >Subject: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > > > > > > > > > > I need a little advise here. I want to test my repeater's > > > > sensitivity through the duplexer's while the transmitter is keyed > > > > up, into my Cushman Service Monitor. What is the best method of > > > > doing this? Do I need an isolator of some sort, or will the service > > > > monitor handle both the incoming power and the outgoing signal > > > > generator? It's a Cushman 6030 by the way. The repeater is working > > > > excellent for the most part. The problem that I am having is on > > > > weak signals, the audio is being chopped out, almost like the PL > > > > deck is shutting down. On the bench, the receiver is at about .25 > > > > microvolts sensitivity at 12 DB Sinad. Audio out of the transmitter > > > > is about 4KHz wide, and clean at 100 watts. Any suggestions. > > > > Handhelds are able to get in from about 4 miles away, mobiles have > > > > no troubles at 30 miles away. The antenna is only up at 60' right > > > > now, fed with 120' of 7/8" Andrews hardline. But it seems the > > > > handhelds are the one's having the problems, and their signal is not > > > > really that bad. Help please. > > > > > > > > Mathew > > > > > > > > > > > > > > > > > > > > > > > > > > > >Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > >Yahoo! Groups Links > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Mathew, No, you should not disturb any of the hookups between your duplexer and antenna, transmitter, or receiver. What I meant by a "separate antenna" is one connected to the output of your service monitor, and which radiates a signal that is picked up by your repeater antenna. This method will prove or disprove whether desense is caused by your own transmitter. It will also enable you to determine if desense is being caused by a nearby transmitter on a different frequency, if the SINAD reading suddenly drops while your repeater transmitter is disabled. If this happens, you can use a spectrum analyzer to sweep the band several MHz each side of your receiver frequency and note what carriers are present at the same time your SINAD drops. As I noted in a previous posting, a bandpass filter may be needed to eliminate desense caused by a nearby transmitter. 73, Eric Lemmon WB6FLY Mathew Quaife wrote: > > Could I get by using a separate antenna to test for desense? Say leaving > the antenna for the receiver through the duplexer and hooking the > transmitter up to another antenna, would that work the same to test for > desense. I tried to make an iso-tee, did not have real good luck with it, > but then as far as a machinist, I have no luck at that, hihi Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Forgot to mention one thing - you don't even need to visit the site if the repeater has an autopatch (or even a remote base that is on a different band) you can listen to the RX via the patch or remote and let the main channel TX time out. If the quieting level in the RX goes up exactly when the TX drops off that indicates a problem. Mike WA6ILQ At 07:14 PM 7/26/04, you wrote: >I like the idea but I'd use a parked mobile instead. HT's are hand held >and can >be moved which will change the signal level, plus they pull 3/4 to 1amp from >the batteries and can suck them down, which also changes the signal level. >The use of a parked mobile - set to the lowest power level it can do - >eliminates >both factors from the equation. > >Mike WA6ILQ > >At 06:57 PM 7/26/04, you wrote: > > >Here's one simple test. Have someone with an HT get into a noisy location, > >then disable your repeater transmitter while listening on the local speaker. > >If all of a sudden the HT becomes full quieting, you've got a desense > >problem. > > > >Chuck > >WB2EDV > > > > > > > >- Original Message - > >From: "w9mwq" <[EMAIL PROTECTED]> > >To: > >Sent: Monday, July 26, 2004 8:01 PM > >Subject: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > > > > > > > I need a little advise here. I want to test my repeater's > > > sensitivity through the duplexer's while the transmitter is keyed > > > up, into my Cushman Service Monitor. What is the best method of > > > doing this? Do I need an isolator of some sort, or will the service > > > monitor handle both the incoming power and the outgoing signal > > > generator? It's a Cushman 6030 by the way. The repeater is working > > > excellent for the most part. The problem that I am having is on > > > weak signals, the audio is being chopped out, almost like the PL > > > deck is shutting down. On the bench, the receiver is at about .25 > > > microvolts sensitivity at 12 DB Sinad. Audio out of the transmitter > > > is about 4KHz wide, and clean at 100 watts. Any suggestions. > > > Handhelds are able to get in from about 4 miles away, mobiles have > > > no troubles at 30 miles away. The antenna is only up at 60' right > > > now, fed with 120' of 7/8" Andrews hardline. But it seems the > > > handhelds are the one's having the problems, and their signal is not > > > really that bad. Help please. > > > > > > Mathew > > > > > > > > > > > > > > > > > > >Yahoo! Groups Links > > > > > > > > > > > > > > >Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Ok, looks like I need to get the Iso-tee made then. Mathew - Original Message - From: "Chuck Kelsey" <[EMAIL PROTECTED]> To: Sent: Monday, July 26, 2004 7:25 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > No. > > > > - Original Message - > From: "Mathew Quaife" <[EMAIL PROTECTED]> > To: > Sent: Monday, July 26, 2004 10:17 PM > Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through > Duplexer > > > > Could I get by using a seperate antenna to test for desense? Say leaving > > the antenna for the receiver through the duplexer and hooking the > > transmitter up to another antenna, would that work the same to test for > > desense. I tried to make an iso-tee, did not heave real good luck with > it, > > but then as far as a machinest, I have to luck at that, hihi > > > > Mathew > > > > - Original Message - > > From: "Eric Lemmon" <[EMAIL PROTECTED]> > > To: > > Sent: Monday, July 26, 2004 6:09 PM > > Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through > > Duplexer > > > > > > > Mathew, > > > > > > There may be more than one problem to consider. It is wise to check for > > > desense, but also be aware that some amateur-grade handhelds are > > > notorious for excessive PL deviation. Alincos are the worst, in my > > > opinion. My DJ-S11T had 1400 Hz of PL deviation out of the box, when > > > 400-700 Hz is ideal. When a commercial-grade repeater (MICOR, GE, etc.) > > > receives an input from a user with excessive PL deviation, the user's > > > voice may over-deviate the carrier, causing the PL to be clipped. When > > > this happens on a PL-required repeater, the repeater shuts down on voice > > > peaks. Of course, this symptom is made much worse when the voice > > > deviation is too high, as well. One way to check this is to use a > > > commercial-grade handheld radio to check for the same symptoms. > > > > > > To check for desense, you can use an "iso-tee" to inject a low-level > > > signal into the antenna feedline at the receiver frequency, while > > > monitoring the receiver audio at 12 dB SINAD with the repeater > > > disabled. Then enable the repeater so that the transmitter turns on. > > > The SINAD reading should drop no more than 1 dB. Some service monitors > > > will change modes when RF is detected, so you may want to use a separate > > > antenna, instead of the iso-tee, to get the test signal into the > > > receiver. > > > > > > If your repeater is at a site with other transmitters, you may need to > > > add some bandpass-only (NOT pass/notch) cavities between the duplexer > > > and the receiver input. As has been noted many times on this list, a > > > pass/notch or "BpBr" duplexer has almost no bandpass selectivity, and a > > > nearby transmitter many MHz away can easily cause desense in your > > > receiver if not filtered out with a dedicated bandpass cavity. > > > > > > 73, Eric Lemmon WB6FLY > > > > > > w9mwq wrote: > > > > > > > > I need a little advice here. I want to test my repeater's sensitivity > > through the duplexer, while the transmitter is keyed up, into my Cushman > > Service Monitor. What is the best method of doing this? Do I need an > > isolator of some sort, or will the service monitor handle both the > incoming > > power and the outgoing signal > > > > generator? It's a Cushman 6030 by the way. The repeater is working > > excellent for the most part. The problem that I am having is on weak > > signals, the audio is being chopped out, almost like the PL deck is > shutting > > down. On the bench, the receiver is at about .25 microvolts sensitivity > at > > 12 dB Sinad. Audio out of the transmitter > > > > is about 4 kHz wide, and clean at 100 watts. Any suggestions? > > Handhelds are able to get in from about 4 miles away, mobiles have no > > troubles at 30 miles away. The antenna is only up at 60' right now, fed > > with 120' of 7/8" Andrews hardline. But it seems the handhelds are the > ones > > having the problems, and their signal is not really that bad. Help > please. > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
No. - Original Message - From: "Mathew Quaife" <[EMAIL PROTECTED]> To: Sent: Monday, July 26, 2004 10:17 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > Could I get by using a seperate antenna to test for desense? Say leaving > the antenna for the receiver through the duplexer and hooking the > transmitter up to another antenna, would that work the same to test for > desense. I tried to make an iso-tee, did not heave real good luck with it, > but then as far as a machinest, I have to luck at that, hihi > > Mathew > > - Original Message - > From: "Eric Lemmon" <[EMAIL PROTECTED]> > To: > Sent: Monday, July 26, 2004 6:09 PM > Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through > Duplexer > > > > Mathew, > > > > There may be more than one problem to consider. It is wise to check for > > desense, but also be aware that some amateur-grade handhelds are > > notorious for excessive PL deviation. Alincos are the worst, in my > > opinion. My DJ-S11T had 1400 Hz of PL deviation out of the box, when > > 400-700 Hz is ideal. When a commercial-grade repeater (MICOR, GE, etc.) > > receives an input from a user with excessive PL deviation, the user's > > voice may over-deviate the carrier, causing the PL to be clipped. When > > this happens on a PL-required repeater, the repeater shuts down on voice > > peaks. Of course, this symptom is made much worse when the voice > > deviation is too high, as well. One way to check this is to use a > > commercial-grade handheld radio to check for the same symptoms. > > > > To check for desense, you can use an "iso-tee" to inject a low-level > > signal into the antenna feedline at the receiver frequency, while > > monitoring the receiver audio at 12 dB SINAD with the repeater > > disabled. Then enable the repeater so that the transmitter turns on. > > The SINAD reading should drop no more than 1 dB. Some service monitors > > will change modes when RF is detected, so you may want to use a separate > > antenna, instead of the iso-tee, to get the test signal into the > > receiver. > > > > If your repeater is at a site with other transmitters, you may need to > > add some bandpass-only (NOT pass/notch) cavities between the duplexer > > and the receiver input. As has been noted many times on this list, a > > pass/notch or "BpBr" duplexer has almost no bandpass selectivity, and a > > nearby transmitter many MHz away can easily cause desense in your > > receiver if not filtered out with a dedicated bandpass cavity. > > > > 73, Eric Lemmon WB6FLY > > > > w9mwq wrote: > > > > > > I need a little advice here. I want to test my repeater's sensitivity > through the duplexer, while the transmitter is keyed up, into my Cushman > Service Monitor. What is the best method of doing this? Do I need an > isolator of some sort, or will the service monitor handle both the incoming > power and the outgoing signal > > > generator? It's a Cushman 6030 by the way. The repeater is working > excellent for the most part. The problem that I am having is on weak > signals, the audio is being chopped out, almost like the PL deck is shutting > down. On the bench, the receiver is at about .25 microvolts sensitivity at > 12 dB Sinad. Audio out of the transmitter > > > is about 4 kHz wide, and clean at 100 watts. Any suggestions? > Handhelds are able to get in from about 4 miles away, mobiles have no > troubles at 30 miles away. The antenna is only up at 60' right now, fed > with 120' of 7/8" Andrews hardline. But it seems the handhelds are the ones > having the problems, and their signal is not really that bad. Help please. > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Very true indeed. I'm thinking it may be a combination of two things. First the handhelds are clipping the PL, I have a commercial Vertex HT, and it does not do it with that, but then I have mine turned down to about 400 Hertz. I'm sure the duplexers were tuned properly, as they were done by a service shop before being shipped, they are TXRX. Mathew > I like the idea but I'd use a parked mobile instead. HT's are hand held > and can > be moved which will change the signal level, plus they pull 3/4 to 1amp from > the batteries and can suck them down, which also changes the signal level. > The use of a parked mobile - set to the lowest power level it can do - > eliminates > both factors from the equation. > > Mike WA6ILQ > > At 06:57 PM 7/26/04, you wrote: > > >Here's one simple test. Have someone with an HT get into a noisy location, > >then disable your repeater transmitter while listening on the local speaker. > >If all of a sudden the HT becomes full quieting, you've got a desense > >problem. > > > >Chuck > >WB2EDV > > > > > > > >- Original Message - > >From: "w9mwq" <[EMAIL PROTECTED]> > >To: > >Sent: Monday, July 26, 2004 8:01 PM > >Subject: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > > > > > > > I need a little advise here. I want to test my repeater's > > > sensitivity through the duplexer's while the transmitter is keyed > > > up, into my Cushman Service Monitor. What is the best method of > > > doing this? Do I need an isolator of some sort, or will the service > > > monitor handle both the incoming power and the outgoing signal > > > generator? It's a Cushman 6030 by the way. The repeater is working > > > excellent for the most part. The problem that I am having is on > > > weak signals, the audio is being chopped out, almost like the PL > > > deck is shutting down. On the bench, the receiver is at about .25 > > > microvolts sensitivity at 12 DB Sinad. Audio out of the transmitter > > > is about 4KHz wide, and clean at 100 watts. Any suggestions. > > > Handhelds are able to get in from about 4 miles away, mobiles have > > > no troubles at 30 miles away. The antenna is only up at 60' right > > > now, fed with 120' of 7/8" Andrews hardline. But it seems the > > > handhelds are the one's having the problems, and their signal is not > > > really that bad. Help please. > > > > > > Mathew > > > > > > > > > > > > > > > > > > >Yahoo! Groups Links > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Could I get by using a seperate antenna to test for desense? Say leaving the antenna for the receiver through the duplexer and hooking the transmitter up to another antenna, would that work the same to test for desense. I tried to make an iso-tee, did not heave real good luck with it, but then as far as a machinest, I have to luck at that, hihi Mathew - Original Message - From: "Eric Lemmon" <[EMAIL PROTECTED]> To: Sent: Monday, July 26, 2004 6:09 PM Subject: Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > Mathew, > > There may be more than one problem to consider. It is wise to check for > desense, but also be aware that some amateur-grade handhelds are > notorious for excessive PL deviation. Alincos are the worst, in my > opinion. My DJ-S11T had 1400 Hz of PL deviation out of the box, when > 400-700 Hz is ideal. When a commercial-grade repeater (MICOR, GE, etc.) > receives an input from a user with excessive PL deviation, the user's > voice may over-deviate the carrier, causing the PL to be clipped. When > this happens on a PL-required repeater, the repeater shuts down on voice > peaks. Of course, this symptom is made much worse when the voice > deviation is too high, as well. One way to check this is to use a > commercial-grade handheld radio to check for the same symptoms. > > To check for desense, you can use an "iso-tee" to inject a low-level > signal into the antenna feedline at the receiver frequency, while > monitoring the receiver audio at 12 dB SINAD with the repeater > disabled. Then enable the repeater so that the transmitter turns on. > The SINAD reading should drop no more than 1 dB. Some service monitors > will change modes when RF is detected, so you may want to use a separate > antenna, instead of the iso-tee, to get the test signal into the > receiver. > > If your repeater is at a site with other transmitters, you may need to > add some bandpass-only (NOT pass/notch) cavities between the duplexer > and the receiver input. As has been noted many times on this list, a > pass/notch or "BpBr" duplexer has almost no bandpass selectivity, and a > nearby transmitter many MHz away can easily cause desense in your > receiver if not filtered out with a dedicated bandpass cavity. > > 73, Eric Lemmon WB6FLY > > w9mwq wrote: > > > > I need a little advice here. I want to test my repeater's sensitivity through the duplexer, while the transmitter is keyed up, into my Cushman Service Monitor. What is the best method of doing this? Do I need an isolator of some sort, or will the service monitor handle both the incoming power and the outgoing signal > > generator? It's a Cushman 6030 by the way. The repeater is working excellent for the most part. The problem that I am having is on weak signals, the audio is being chopped out, almost like the PL deck is shutting down. On the bench, the receiver is at about .25 microvolts sensitivity at 12 dB Sinad. Audio out of the transmitter > > is about 4 kHz wide, and clean at 100 watts. Any suggestions? Handhelds are able to get in from about 4 miles away, mobiles have no troubles at 30 miles away. The antenna is only up at 60' right now, fed with 120' of 7/8" Andrews hardline. But it seems the handhelds are the ones having the problems, and their signal is not really that bad. Help please. > > > > > > Yahoo! Groups Links > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
I like the idea but I'd use a parked mobile instead. HT's are hand held and can be moved which will change the signal level, plus they pull 3/4 to 1amp from the batteries and can suck them down, which also changes the signal level. The use of a parked mobile - set to the lowest power level it can do - eliminates both factors from the equation. Mike WA6ILQ At 06:57 PM 7/26/04, you wrote: >Here's one simple test. Have someone with an HT get into a noisy location, >then disable your repeater transmitter while listening on the local speaker. >If all of a sudden the HT becomes full quieting, you've got a desense >problem. > >Chuck >WB2EDV > > > >- Original Message - >From: "w9mwq" <[EMAIL PROTECTED]> >To: >Sent: Monday, July 26, 2004 8:01 PM >Subject: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > > > > I need a little advise here. I want to test my repeater's > > sensitivity through the duplexer's while the transmitter is keyed > > up, into my Cushman Service Monitor. What is the best method of > > doing this? Do I need an isolator of some sort, or will the service > > monitor handle both the incoming power and the outgoing signal > > generator? It's a Cushman 6030 by the way. The repeater is working > > excellent for the most part. The problem that I am having is on > > weak signals, the audio is being chopped out, almost like the PL > > deck is shutting down. On the bench, the receiver is at about .25 > > microvolts sensitivity at 12 DB Sinad. Audio out of the transmitter > > is about 4KHz wide, and clean at 100 watts. Any suggestions. > > Handhelds are able to get in from about 4 miles away, mobiles have > > no troubles at 30 miles away. The antenna is only up at 60' right > > now, fed with 120' of 7/8" Andrews hardline. But it seems the > > handhelds are the one's having the problems, and their signal is not > > really that bad. Help please. > > > > Mathew > > > > > > > > > >Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Here's one simple test. Have someone with an HT get into a noisy location, then disable your repeater transmitter while listening on the local speaker. If all of a sudden the HT becomes full quieting, you've got a desense problem. Chuck WB2EDV - Original Message - From: "w9mwq" <[EMAIL PROTECTED]> To: Sent: Monday, July 26, 2004 8:01 PM Subject: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer > I need a little advise here. I want to test my repeater's > sensitivity through the duplexer's while the transmitter is keyed > up, into my Cushman Service Monitor. What is the best method of > doing this? Do I need an isolator of some sort, or will the service > monitor handle both the incoming power and the outgoing signal > generator? It's a Cushman 6030 by the way. The repeater is working > excellent for the most part. The problem that I am having is on > weak signals, the audio is being chopped out, almost like the PL > deck is shutting down. On the bench, the receiver is at about .25 > microvolts sensitivity at 12 DB Sinad. Audio out of the transmitter > is about 4KHz wide, and clean at 100 watts. Any suggestions. > Handhelds are able to get in from about 4 miles away, mobiles have > no troubles at 30 miles away. The antenna is only up at 60' right > now, fed with 120' of 7/8" Andrews hardline. But it seems the > handhelds are the one's having the problems, and their signal is not > really that bad. Help please. > > Mathew > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Receiver Sensitivity Testing Through Duplexer
Mathew, There may be more than one problem to consider. It is wise to check for desense, but also be aware that some amateur-grade handhelds are notorious for excessive PL deviation. Alincos are the worst, in my opinion. My DJ-S11T had 1400 Hz of PL deviation out of the box, when 400-700 Hz is ideal. When a commercial-grade repeater (MICOR, GE, etc.) receives an input from a user with excessive PL deviation, the user's voice may over-deviate the carrier, causing the PL to be clipped. When this happens on a PL-required repeater, the repeater shuts down on voice peaks. Of course, this symptom is made much worse when the voice deviation is too high, as well. One way to check this is to use a commercial-grade handheld radio to check for the same symptoms. To check for desense, you can use an "iso-tee" to inject a low-level signal into the antenna feedline at the receiver frequency, while monitoring the receiver audio at 12 dB SINAD with the repeater disabled. Then enable the repeater so that the transmitter turns on. The SINAD reading should drop no more than 1 dB. Some service monitors will change modes when RF is detected, so you may want to use a separate antenna, instead of the iso-tee, to get the test signal into the receiver. If your repeater is at a site with other transmitters, you may need to add some bandpass-only (NOT pass/notch) cavities between the duplexer and the receiver input. As has been noted many times on this list, a pass/notch or "BpBr" duplexer has almost no bandpass selectivity, and a nearby transmitter many MHz away can easily cause desense in your receiver if not filtered out with a dedicated bandpass cavity. 73, Eric Lemmon WB6FLY w9mwq wrote: > > I need a little advice here. I want to test my repeater's sensitivity > through the duplexer, while the transmitter is keyed up, into my Cushman > Service Monitor. What is the best method of doing this? Do I need an > isolator of some sort, or will the service monitor handle both the incoming > power and the outgoing signal > generator? It's a Cushman 6030 by the way. The repeater is working > excellent for the most part. The problem that I am having is on weak > signals, the audio is being chopped out, almost like the PL deck is shutting > down. On the bench, the receiver is at about .25 microvolts sensitivity at > 12 dB Sinad. Audio out of the transmitter > is about 4 kHz wide, and clean at 100 watts. Any suggestions? Handhelds are > able to get in from about 4 miles away, mobiles have no troubles at 30 miles > away. The antenna is only up at 60' right now, fed with 120' of 7/8" Andrews > hardline. But it seems the handhelds are the ones having the problems, and > their signal is not really that bad. Help please. Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Receiver Sensitivity Testing Through Duplexer
--- In Repeater-Builder@yahoogroups.com, "w9mwq" <[EMAIL PROTECTED]> wrote: "...I want to test my repeater's sensitivity through the duplexer's while the transmitter is keyed up..." __ ___ Start by reading this: http://www.repeater-builder.com/rbtip/effectivesens.html What you want to do is first test the repeater for desense with the transmitter operating into a 50 ohm load. The receiver should have the same sensitivity through the iso-T with the transmitter off or on. If not, you have an issue with your duplexer. Once you have the station operating properly into a load, then begin the test at the site. You are looking for two issues. 1. Is the receiver being desensed by site noise? 2. Does the repeater operate without desense [or without any more desense than observed in step 1] when the repeater transmitter is active and the system is using its antenna. Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
