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Suggestions for service monitor


 

With SDR being a thing these days, is there any software that could turn say a BladeRF into a capable service monitor for duplexer tuning and alignment? Or any off the shelf solutions which just connect to a computer with USB for operating the service monitor so you don't need the expense of a box with everything in it, similar to the USB oscilloscopes?
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If not, what is the best bang-for-your-buck ebay-able service monitor that is suitable for most basic service/alignment tasks on repeaters/mobiles/duplexers?
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Thanks,
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Mike


 

Motorola R2600 series with tracking generator option.
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One and done.
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Chris/AJM
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--
Chris Baldwin, CETSr. (KF6AJM)
Trustee - MetroNET Cal. Intertie (KB3PX)


 

Try a LibreVNA. They are both a VNA and Spectrum Analyzer that run though USB to a computer.?
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Rob VK5TRM


 

Ramsey COM3010
It does everything I need for AM/FM communication transceivers and duplexer tuning.

Alan N2ZVN

On Sun, Apr 6, 2025 at 9:49?AM Mike Bernardo KI5ANU via <mike=[email protected]> wrote:
With SDR being a thing these days, is there any software that could turn say a BladeRF into a capable service monitor for duplexer tuning and alignment? Or any off the shelf solutions which just connect to a computer with USB for operating the service monitor so you don't need the expense of a box with everything in it, similar to the USB oscilloscopes?
?
If not, what is the best bang-for-your-buck ebay-able service monitor that is suitable for most basic service/alignment tasks on repeaters/mobiles/duplexers?
?
Thanks,
?
Mike


 

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Thanks! Pricey though, except maybe for the CRT models. Makes me a little nervous to go spending $2500 on something with an old CRT in it. I was just reading this here which is interesting, some amount of restoration is possible and I wonder if any of these SimmComm Labs LCD replacements would work for a Motorola service monitor:?

Mike

On Apr 6, 2025, at 09:43, Chris Baldwin via groups.io <vtat1271@...> wrote:

Motorola R2600 series with tracking generator option.
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One and done.
?
Chris/AJM
?
--
Chris Baldwin, CETSr. (KF6AJM)
Trustee - MetroNET Cal. Intertie (KB3PX)


 

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Ooh this is interesting. I have a NanoVNA and I think I asked here and also saw some other threads here that were saying its dynamic range is not enough to tune a duplexer. LibreVNA looks a lot more capable!

Mike

On Apr 6, 2025, at 14:38, Rob VK5TRM via groups.io <vk5trm@...> wrote:

Try a LibreVNA. They are both a VNA and Spectrum Analyzer that run though USB to a computer.?
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Rob VK5TRM


 

At 4/6/2025 01:35 PM, you wrote:
Ooh this is interesting. I have a NanoVNA and I think I asked here and also saw some other threads here that were saying its dynamic range is not enough to tune a duplexer. LibreVNA looks a lot more capable!

I've seen reports of drift issues with the LibraVNA.? For the moment I'm happy with my VNWA 3EC (though the design is getting dated so not sure I'd recommend for a new purchase), but if I needed one today I'd try this one: <>

Bob NO6B


 

The NanoVNA-V2 seems to handle doing the pass part pretty well. You're measuring return loss there, and it seems to handle that just fine. Only question I might se is if the frequency standard is really accurate enough to set it correctly-but I bet it's pretty close...
Notches on the other hand-forget it. Definitely not even close to enough range for that. Even most service monitors can't do it, or are right on the edge of doing tolerably.

On 4/6/2025 5:34 PM, Bob Dengler via groups.io wrote:
At 4/6/2025 01:35 PM, you wrote:
Ooh this is interesting. I have a NanoVNA and I think I asked here and also saw some other threads here that were saying its dynamic range is not enough to tune a duplexer. LibreVNA looks a lot more capable!
I've seen reports of drift issues with the LibraVNA.? For the moment I'm happy with my VNWA 3EC (though the design is getting dated so not sure I'd recommend for a new purchase), but if I needed one today I'd try this one: < <>>
Bob NO6B
_._,_._,_


 

For non digital stuff the HP/Agilent 8920 series.?


 

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I second this. I had the same question about a month ago and ended up getting an HP8921A. It¡¯s a good analyzer to learn on and does probably way more than you need.?


On Apr 7, 2025, at 6:42?PM, Mike via groups.io <prcradio@...> wrote:

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For non digital stuff the HP/Agilent 8920 series.?


 

I bought a Motorola R2600C for $600 and then about a week later picked up a Motorola R2550 with tracking generator for $400. I already have a Rigol DSA815TG spectrum analyzer that I use for filter tuning.


 

Third.

Bob NO6B

At 4/7/2025 03:47 PM, you wrote:

I second this. I had the same question about a month ago and ended up getting an HP8921A. It?€?s a good analyzer to learn on and does probably way more than you need.


On Apr 7, 2025, at 6:42?€?PM, Mike via groups.io <prcradio@...> wrote:

???
For non digital stuff the HP/Agilent 8920 series.


 

Mike,
This is a Windows program, but I think it's a lot of what you want and you can choose the hardware
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Steve N4IRS


 

The Motorola 2600 series is hard to beat... And can be found reasonably priced if you are patient.


On Tue, Apr 8, 2025, 7:10?AM Steve N4IRS via <szingman=[email protected]> wrote:
Mike,
This is a Windows program, but I think it's a lot of what you want and you can choose the hardware
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Steve N4IRS