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Re: VHF MTR2000 Poor Receive Performance
Hopefully he did the test below with the TX disabled. If not, they don't tell us much.
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Mike WM4B On November 2, 2022 at 8:36 AM John <jhaserick84@...> wrote: ? ? |
Re: TKR-851 power issue
Did you measure the voltage at the PA transistor? I'd look at that first. Also measure the exciter output and see what it's doing. If I recall correctly, the repeater uses a relay to switch in and out a dropping resistor for backup DC operation. I've seen that really fail or the circuit land open up. I had a TKR 750 that acted the same way but it had been underwater for 7 weeks after tropical storm Harvey! It worked for about 10 minutes until the microprocessor went crazy. Chris WB5ITT? On Wed, Nov 2, 2022, 7:50 AM Brandon Vetter <Brandon@...> wrote:
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TKR-851 power issue
¿ªÔÆÌåÓýHi Group, ????????????? I have a TKR-851 that I thought had bad finals. It had about 2 watts output. Installed a new transmitter board with new driver and final transistors and now I get 3 Watts output. If I drop it to low power, I get less than 1 watt. The power in the software is turned up. The power adjustment pot does not seem to be functional. There are no PLL errors flashing. Anyone have any thoughts on what might be going on? ? Brandon Vetter N7IRG ? ? |
Re: VHF MTR2000 Poor Receive Performance
Hello Jared,
I have not been following these threads very carefully, but the thought occurred to me wondering if your transmitter might have spurs when connected to the duplexer? It would be easy enough to check with a spectrum analyzer connected via a lossy T between the TX and duplexer, (if not already checked.)? I had just finished working on a Spectrum repeater that did have spurs close to the TX frequency, corrected by retuning each stage while watching the spur level drop until they disappeared.
John W1GPO
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Re: VHF MTR2000 Poor Receive Performance
So last night, I measured the MTR at 0.4uV at the receiver port and 0.5uV at the duplexer antenna port.
I injected a signal into the receiver port of the MTR that had just barely had no noise and when I injected it through the duplexer into the repeater, there was noise present. It wasn't heavy noise but it still had noise on the signal. |
Re: Somewhat OT... imaging a hard drive...
¿ªÔÆÌåÓýHi guys,Taxing the brain, With XP, one had to mod the registry to go back to the bios for
the disk driver if the motherboard IDE or SATA driver changes. Then at first boot
on the new hardware, it will install the appropriate hard disk driver and video drivers.
Can anybody remember the details?
Alan VK2ZIW
On Wed, 02 Nov 2022 01:49:04 -0700, M M wrote
> I asked the seller which version of Ghost he was providing as I was looking for 7 or later. > He replied "I think this is version 3 or older, Not what you are looking for." >
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Re: Somewhat OT... imaging a hard drive...
I asked the seller which version of Ghost he was providing as I was looking for 7 or later.
He replied "I think this is version 3 or older, Not what you are looking for."
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Re: Connecting Yaesu DR2X Repeater to Raspberry Pi/Allstar?
Chris Smart
¿ªÔÆÌåÓýThanks Steve. ? ? ? 73, Chris ? ? From: [email protected] <[email protected]> On Behalf Of N8AR
Sent: November 1, 2022 9:09 PM To: [email protected] Subject: Re: [repeater-builder] Connecting Yaesu DR2X Repeater to Raspberry Pi/Allstar? ? Here is a link to a program called PiTone which can be used to create a CTCSS tone.? PiTone runs on a Raspberry Pi (can be the same one that is running Allstar).? It uses a D/A converter connected to the I2C bus to create a stepped sinewave which is easy to filter to a "pure" sinwave. |
Re: Connecting Yaesu DR2X Repeater to Raspberry Pi/Allstar?
Here is a link to a program called PiTone which can be used to create a CTCSS tone.? PiTone runs on a Raspberry Pi (can be the same one that is running Allstar).? It uses a D/A converter connected to the I2C bus to create a stepped sinewave which is easy to filter to a "pure" sinwave.
We have used it on our local repeaters (DR-1X and Micor) for more than 4 years. Steve - N8AR |
Re: VHF MTR2000 Poor Receive Performance
¿ªÔÆÌåÓýJared,
We need to quantify why (and when) the repeater is "deaf". Next time you're at the site, do the following: 1 - Disconnect the repeater from the duplexer.? 2 - Connect the repeater antenna to the receiver - directly.? 3 - Terminate the transmitter into a suitable dummy load. 4 - Get a friend to help or use the service monitor to produce a weak signal into the repeater.? This must be a stable emission that's repeatable.? It can't be full quieting - some noise needs to be preset to detect a change in quieting. 5 - Reconnect the antenna to the duplexer, and receiver to the duplexer, but do NOT connect the transmitter - - leave it on the load. 6 - Compare the signal quality (quieting) between the antenna being connected directly to the receiver and additionally through the duplexer.? At 1.67 dB IL - they should be virtually identical. ** If there is little/no difference between the signal level with the antenna connected directly to the receiver and through the receive path of the duplexer, the 'disappointment' is not the duplexers' fault.? You could swap in a different receiver, even a HT temporarily to see how well it hears in comparison.? Just remove whatever you substitute and reconnect the repeater's receiver before you continue. 7 - Remove the transmitter from the load and connect the transmitter to the duplexer. 8 - Wire a toggle switch into the PTT lead to instantly disable the repeaters transmitter. 9 - Compare the weak signal with the transmitter "ON" and "OFF".? They should be virtually identical. A - If there's a notable difference in quieting with the antenna connected directly to the receiver and then through the receive path of the duplexer - the RX path insertion loss isn't really 1.67dB. B - If there's a difference in quieting between when the repeater transmitter is on and off - you have classic desense. Let us know the results. Kevin On 11/1/2022 6:55 PM, Jared Smudde wrote: So the transmit side cavities all have 29db-32db of return loss at pass frequency, 30db of notch rejection and 0.4db of IL at the pass frequencies. |
Re: VHF MTR2000 Poor Receive Performance
I think we need to redefine 'deaf'. What are the current 12dB SINAD 1) at the receiver port, and 2) at the antenna port of the duplexer? (Those values were previously reported as 0.40 and 0.53 uV respectively.)
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Originally the problem was reported as " basically deaf to 5 watt portables barely a mile from my house, mobiles work a bit further" and about 1 dB of desense was reported. We need to make sure we're comparing apples to apples. At this point, portable or mobile coverage and anything to do with the antenna system (except the duplexer) needs to be OUT of the equation. Measurements all need to be made using the same test cables and the same signal generator/service monitor. Anything else introduces errors/uncertainties. The receiver itself (with no TX engaged) needs to be baselined to see if it meets specs (0.35 uV for 12 dB SINAD I believe), and if it does not, that needs to be addressed. Adding in the duplexer, sensitivity should decrease only by the amount of loss previously recorded in the Pass. If the Pass is measured as 'X' and the receiver sensitivity decreases by more-than-'X', than something is amiss at the Circle K and investigation needs to determine the cause. Sometimes it's helpful to take a day off, go poke .45 caliber holes in paper, then come back to it with a fresh mind, starting over at square one. My 2-cents worth. Mike WM4B -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of MILLIN SEE Sent: Tuesday, November 1, 2022 8:09 PM To: [email protected] Subject: Re: [repeater-builder] VHF MTR2000 Poor Receive Performance Sounds like your forcing that duplexer outside it's parameter. Millin ----- Original Message ----- From: Jared Smudde <computerwhiz02@...> To: [email protected] Sent: Tue, 01 Nov 2022 16:55:15 -0600 (MDT) Subject: Re: [repeater-builder] VHF MTR2000 Poor Receive Performance So the transmit side cavities all have 29db-32db of return loss at pass frequency, 30db of notch rejection and 0.4db of IL at the pass frequencies. I went to the receive cavity causing trouble and slid the tuning rod all the way up and cleaned the rod with some fine sandpaper and wiped it down with denatured alcohol. I then took the rod and ran it up and down the cavity several times all while rotating the rod at the same time. I was able to get the return loss to 30DB on the cavity. Probably had to clean some varnish off of the rod and tuning fingers. I reattached the harness and each side had about 1.67db of insertion loss and I was able to get the notch over 105db on each side. I hooked up the repeater and was met with disappointment, repeater is still deaf with no improvement. |
Re: VHF MTR2000 Poor Receive Performance
Sounds like your forcing that duplexer outside it's parameter.
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Millin ----- Original Message -----
From: Jared Smudde <computerwhiz02@...> To: [email protected] Sent: Tue, 01 Nov 2022 16:55:15 -0600 (MDT) Subject: Re: [repeater-builder] VHF MTR2000 Poor Receive Performance So the transmit side cavities all have 29db-32db of return loss at pass frequency, 30db of notch rejection and 0.4db of IL at the pass frequencies. I went to the receive cavity causing trouble and slid the tuning rod all the way up and cleaned the rod with some fine sandpaper and wiped it down with denatured alcohol. I then took the rod and ran it up and down the cavity several times all while rotating the rod at the same time. I was able to get the return loss to 30DB on the cavity. Probably had to clean some varnish off of the rod and tuning fingers. I reattached the harness and each side had about 1.67db of insertion loss and I was able to get the notch over 105db on each side. I hooked up the repeater and was met with disappointment, repeater is still deaf with no improvement. |
Re: VHF MTR2000 Poor Receive Performance
So the transmit side cavities all have 29db-32db of return loss at pass frequency, 30db of notch rejection and 0.4db of IL at the pass frequencies.
I went to the receive cavity causing trouble and slid the tuning rod all the way up and cleaned the rod with some fine sandpaper and wiped it down with denatured alcohol. I then took the rod and ran it up and down the cavity several times all while rotating the rod at the same time. I was able to get the return loss to 30DB on the cavity. Probably had to clean some varnish off of the rod and tuning fingers. I reattached the harness and each side had about 1.67db of insertion loss and I was able to get the notch over 105db on each side. I hooked up the repeater and was met with disappointment, repeater is still deaf with no improvement. |
Re: Windows 7 config
I am not using a repeater. Just using vara fm and winlink. Will be using a cdm1250. Just looking for information on the software side. Sorry for stirring the pot
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Re: Somewhat OT... imaging a hard drive...
I know it has been proposed?but I use ? it works on any pc, 32 bit or 64. And if you plug a MAC SATA disk into an external drive bay it will even make a nice image of it or even duplicate it to a new drive.Works on IDE and on SSD's even works on USB attached drive.? Simple GUI and the main thing, it is free! Le?lun. 31 oct. 2022 ¨¤?14:49, wj9jrg <wj9jrg@...> a ¨¦crit?:
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Re: Windows 7 config
Ok...I obviously missed the data part lol... Chris WB5ITT? On Tue, Nov 1, 2022, 12:59 PM Scott Currie <scott.d.currie@...> wrote: Correct, we're not talking about repeaters here. We are taking discriminator audio to the sound card interface for decoding, and sending modulated data from the sound card to the modulator. Obviously if you set the transmit gain too high you will cause interference on adjacent channels. And it will also destroy the data being sent, so a really bad idea. |
Re: Windows 7 config
Correct, we're not talking about repeaters here. We are taking discriminator audio to the sound card interface for decoding, and sending modulated data from the sound card to the modulator. Obviously if you set the transmit gain too high you will cause interference on adjacent channels. And it will also destroy the data being sent, so a really bad idea.
This discussion would be better handled on the Winlink and Vara forums: /g/VARA-MODEM/topics -Scott, NS7C |
Re: UHF Cans?
Your pic appears to be a UHF loop. Measuring one out of a 10" UHF cavity I have here, from the loop plate to the bottom of the loop is about 1.05" (about 1-1/16"), outside width of the loop is about 0.62" (about 5/8").Looks small enough to be UHF. I can verify when I get home tonight.That would be great! Thanks Jeff. If you don't have a use for those, let me know, maybe we can trade for something you need. --- Jeff WN3A -- This email has been checked for viruses by Avast antivirus software. www.avast.com |