What is the best / easiest to work with equipment to use to tune duplexers?
I really do not want to spend a whole lot of money, but I need to be able to tune my duplexers as I'm not able to run down to the corner MSS or radio shop (read: I'm in Spain).
I would LOVE to find a "combination" unit that would include a signal genrator and would allow me to tune radios too.
Any suggestions?
I don't want to spend more than $1500.00
Is that too much to ask?
Duplexer Tuning Equipment???
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RESCUE161
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Duplexer Tuning Equipment???
Scott
KE4FHH
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KE4FHH
Religion: Kills folks dead!
"I don't want to spend more than $1500.00
Is that too much to ask?"
No Scott, it is not. How about one of the later service monitors with the tracking generator option?
If it is a NOTCH NOTCH duplexer? you may be able to use a signal generator some 50 pads, double shielded cables and tune for the minimum signal at the notch freq. on a receiver.
Is that too much to ask?"
No Scott, it is not. How about one of the later service monitors with the tracking generator option?
If it is a NOTCH NOTCH duplexer? you may be able to use a signal generator some 50 pads, double shielded cables and tune for the minimum signal at the notch freq. on a receiver.
Nobody that I know of, new. However, you should be able to find an older 1200S with tracker, or an older COM-120B or 1600S on eBay for those sorts of prices.RKG wrote:Who makes a decent service monitor with a tracking generator for $1500?
Of course, you might be able to find "those other guys" gear on eBay for comparable prices.
I've not tried it, but the newer MFJ antenna tuners might also be able to be used to tune each individual cavity, although you wouldn't be able to check the whole assembly as the MFJ's (IIRC) don't have an independent output and input.
I don't think the Ramsey unit has a spec-an in it.
I suppose if you had an oscilloscope, an RF detector probe, an RF sig-gen, and an audio sig-gen, you could make a poor man's spec-an by:
1) Modulate the RF sig-gen with the audio sig-gen.
2) Set the scope for x/y mode.
3) Drive the scope's X with the audio sig gen.
4) Feed the RF sig gen into the duplexer.
5) Look at the cavity output with the RF detector probe on the scope's Y input.
This is my opinion, not Aeroflex's.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
I have also noticed IFR A-7550 spectrum analyzers with the tracking generator option selling on ebay in the $1500.00 price range lately.
In most cases, this instrument would be better at spectrum analyzer and tracking generator tasks than the spectrum analyzer feature built into service monitors.
Later you could add an inexpensive [used] basic service monitor such as an IFR 500 or 1000, a Motorola R2200, or a Marconi 2955. A service monitor without a built in spectrum analyzer will be less money than one with all the bells and whistles, plus, with two instruments you have more versatility.
In most cases, this instrument would be better at spectrum analyzer and tracking generator tasks than the spectrum analyzer feature built into service monitors.
Later you could add an inexpensive [used] basic service monitor such as an IFR 500 or 1000, a Motorola R2200, or a Marconi 2955. A service monitor without a built in spectrum analyzer will be less money than one with all the bells and whistles, plus, with two instruments you have more versatility.
The equipment I used for the first duplexer I ever tuned was nothing more than a portable, a transceiver with an S meter and some fixed and adjustable attenuators. The duplexer was a four-cavity hybrid ring type.
These duplexers can provide more than 100 dB isolation, well beyond my measurement abilities at the time.
Nand.
I forgot to mention that I also used a Bird wattmeter and a 50-ohm dummy load.
Nand.
These duplexers can provide more than 100 dB isolation, well beyond my measurement abilities at the time.
Nand.
I forgot to mention that I also used a Bird wattmeter and a 50-ohm dummy load.
Nand.
Last edited by Nand on Thu Oct 13, 2005 1:38 pm, edited 1 time in total.
Tuning duplexers is not the easiest thing to do - even with the proper equipment. I have a UHF 4 cavity duplexer that took me over 3 hours to align, and it still wasn't 100% right. Gave it to my equipment tech, and it took him 2 hours to get it perfect using his HP network analyzer.
I was able to tune the duplexer with my HP8558B SA with tracking generator, just don't expect it to be completed in 15 minutes.
Many multiple cavity duplexers use coax cables to connect the individual cavities. Once the duplexer is tuned, you can NOT change these interconnect coax cables without retuning the duplexer. Just moving certain interconnects will change the duplexer center frequency.
You may want to look into a HP 8558B spectrum analyzer and tracking generator. I picked up mine for $800 with calibration certificate.
Also remember some old duplexers contain lots of pure silver. We guestimate my UHF duplexer has 1-3 pounds of silver in it.
I was able to tune the duplexer with my HP8558B SA with tracking generator, just don't expect it to be completed in 15 minutes.
Many multiple cavity duplexers use coax cables to connect the individual cavities. Once the duplexer is tuned, you can NOT change these interconnect coax cables without retuning the duplexer. Just moving certain interconnects will change the duplexer center frequency.
You may want to look into a HP 8558B spectrum analyzer and tracking generator. I picked up mine for $800 with calibration certificate.
Also remember some old duplexers contain lots of pure silver. We guestimate my UHF duplexer has 1-3 pounds of silver in it.
Tuning Duplexers
My two bits worth:
The test equipment required depends on the particular type of duplexer, as well as the test equipment at hand.
There are certainly devices that are best tuned with a tracking generator, however very satisfactory results can be obtained with far less complicated equipment.
A calibrated signal source ( RF generator or service monitor) as well as some means of detecting the RF signal, such as a Spectrum Analyzer, or a tunable receiver.
I have some instructions in MS Word format that I could send you that cover duplexer tuning as well as measuring the performance after you have finished tuning the duplexer.
The test equipment required depends on the particular type of duplexer, as well as the test equipment at hand.
There are certainly devices that are best tuned with a tracking generator, however very satisfactory results can be obtained with far less complicated equipment.
A calibrated signal source ( RF generator or service monitor) as well as some means of detecting the RF signal, such as a Spectrum Analyzer, or a tunable receiver.
I have some instructions in MS Word format that I could send you that cover duplexer tuning as well as measuring the performance after you have finished tuning the duplexer.
Aloha, Bernie
Re: Tuning Duplexers
Would you please send me the MS document? I would like to check it out, and I'd probably learn something.bernie wrote: I have some instructions in MS Word format that I could send you that cover duplexer tuning as well as measuring the performance after you have finished tuning the duplexer.
Thanks bernie
Right now silver is trading at $7.65 an ounce.
Just thought I would point out that your estimate of 1 to 3 pounds of silver in the duplexer are kind of off the mark. What you have is silver plated material like probably copper. The amount od silver used to plate all the cavities is probably no more than a couple of ounces. Sorry to bust your buble.
Jim
Just thought I would point out that your estimate of 1 to 3 pounds of silver in the duplexer are kind of off the mark. What you have is silver plated material like probably copper. The amount od silver used to plate all the cavities is probably no more than a couple of ounces. Sorry to bust your buble.
Jim
Hightower wrote: Also remember some old duplexers contain lots of pure silver. We guestimate my UHF duplexer has 1-3 pounds of silver in it.
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Microwave Mike
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tunafish
Cheap and dirty tuning of Duplexers.....................
Well get a HP 8656A signal generator, pay no more that $ 500.00.
Get a mini-circuit-labs amp to boost it up to 3 watts on flea-bay,
pay no more than $ 150. Make sure it is in the frequency range you need.
Now get a Boonton RF volt meter or a microwatt power meter. The voltmeter is good to about 1 Ghz, the microwatt meters are good to several Ghz, depending on the range of the pick-up head. Pay no more than........say $ 300 with pick-up head or Rf probe and acc.
Now you have a signal source good from .1 to 990 Mhz. A amp good for
the first 500 Mhz or a second amp good from 500 Mhz to 1000 mhz at good power. A detector system, RF voltmeter or power meter.
You should have a little left over to pick up some good quality cables, adapters, and maybe even a good directonal coupler.
With that set up you CAN tune up duplexers, check out the sensitivty of recievers, measure power, trouble shoot amps stage by stage, ect.
Or you can save up and get a good network analyzer..........say around
$8000 with test set.
A spectrum analyzer with tracking generator will also work but I doubt you
will find one in your budget. Your detector system needs a dynamic range of at least 90 Dbm. This will allow you to see the deep notches, at the same time you need to resolve to at least .5 Dbm to see system loss in the bandpass.
Hope this helps
mm
Well get a HP 8656A signal generator, pay no more that $ 500.00.
Get a mini-circuit-labs amp to boost it up to 3 watts on flea-bay,
pay no more than $ 150. Make sure it is in the frequency range you need.
Now get a Boonton RF volt meter or a microwatt power meter. The voltmeter is good to about 1 Ghz, the microwatt meters are good to several Ghz, depending on the range of the pick-up head. Pay no more than........say $ 300 with pick-up head or Rf probe and acc.
Now you have a signal source good from .1 to 990 Mhz. A amp good for
the first 500 Mhz or a second amp good from 500 Mhz to 1000 mhz at good power. A detector system, RF voltmeter or power meter.
You should have a little left over to pick up some good quality cables, adapters, and maybe even a good directonal coupler.
With that set up you CAN tune up duplexers, check out the sensitivty of recievers, measure power, trouble shoot amps stage by stage, ect.
Or you can save up and get a good network analyzer..........say around
$8000 with test set.
A spectrum analyzer with tracking generator will also work but I doubt you
will find one in your budget. Your detector system needs a dynamic range of at least 90 Dbm. This will allow you to see the deep notches, at the same time you need to resolve to at least .5 Dbm to see system loss in the bandpass.
Hope this helps
mm
Re: tunafish
Microwave Mike wrote: A spectrum analyzer with tracking generator will also work but I doubt you
will find one in your budget. Your detector system needs a dynamic range of at least 90 Dbm.
Not quite true - you don't need a 90 dB dynamic range on the analyzer if you tune the passband (with the tracking generator at, say, -20 dBm), then tune the notch, increasing the tracking generator level as you get a better tune, until you have the generator at +10 dBm - that adds 30 dB of range to your measurements. You cannot sweep the whole thing at once, true, but you can tune it. I've done that very thing with my COM-120B tuning a 6 cavity duplexer for 100 dB rejection.
The idea of tuning a duplexer without being able to see the contributions of the various components - seeing the notches move on the spectrum as you make adjustments - just gives me the willies.
This is my opinion, not Aeroflex's.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
http://www.repeater-builder.com/sinclai ... ctions.pdf
Here are the hybrid ring duplexer tuning instructions as written up by Sinclair in 1966 for their hybrid ring duplexer. As you can see, it only uses equipment that was commonly available at the time. This same setup and procedure can still produce similar results with today’s duplexers. In this example, the duplexer is considered tuned when it meets the specs. If so, it is assumed that the frequency response is like the shown graphs.
It may surprise you to see that the cables used for measurement were RG-58/u types. If the required isolation was higher, RG-8A/u or RG-213/u was suggested. And double shielded cable only where the isolation needed was greater than 100dB.
Also imagine having to change the frequency for these duplexers where every cable in the ring is specifically cut for the needed frequency. That is 16 cables for a 4-cavity duplexer with each cable using 2 type N connectors all interconnected using 17 T connectors.
Nand.
Here are the hybrid ring duplexer tuning instructions as written up by Sinclair in 1966 for their hybrid ring duplexer. As you can see, it only uses equipment that was commonly available at the time. This same setup and procedure can still produce similar results with today’s duplexers. In this example, the duplexer is considered tuned when it meets the specs. If so, it is assumed that the frequency response is like the shown graphs.
It may surprise you to see that the cables used for measurement were RG-58/u types. If the required isolation was higher, RG-8A/u or RG-213/u was suggested. And double shielded cable only where the isolation needed was greater than 100dB.
Also imagine having to change the frequency for these duplexers where every cable in the ring is specifically cut for the needed frequency. That is 16 cables for a 4-cavity duplexer with each cable using 2 type N connectors all interconnected using 17 T connectors.
Nand.
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440roadrunner
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I'm certainly no expert on tuning duplexers, but how about a sweep generator?
I have a Wavetek 1002, for example, and it has the external marker option, which wil accomodate a marker, even inputted from my handheld, or any other sig gen. That generator will handle VHF low and high band, as well as UHF.
You'll need a good RF diode detector, probably a couple of inline attenuators for isolation, and a "not very good" oscilloscope with X/Y inputs, for display.
Add to this, a multi port return loss bridge and you have a useful setup for a fraction of the cost of a service monitor.
Another pair of tools I've had fun with is an HP 180 series display (or 853A), with 8558B spectrum analyzer module, and an 8444 tracking gen. One disadvantage to that, is that the tracking generator does not have a directly calibrated output.
I have a Wavetek 1002, for example, and it has the external marker option, which wil accomodate a marker, even inputted from my handheld, or any other sig gen. That generator will handle VHF low and high band, as well as UHF.
You'll need a good RF diode detector, probably a couple of inline attenuators for isolation, and a "not very good" oscilloscope with X/Y inputs, for display.
Add to this, a multi port return loss bridge and you have a useful setup for a fraction of the cost of a service monitor.
Another pair of tools I've had fun with is an HP 180 series display (or 853A), with 8558B spectrum analyzer module, and an 8444 tracking gen. One disadvantage to that, is that the tracking generator does not have a directly calibrated output.
filters
My two bits worth:
I recall that manual very well, along with the Motorola T1500 manual.
I have had to tune these duplexers with out all these fancy tracking generators because in the early '70s they were not commonly available.
The only one was in the enginering office in Honolulu.
I could not tell the coustomer to wait for 25 years or so for the proper equipment to become available.
On a mountain top on the island of Tinian in the Northeren Marianas Islands or on Navy Hill On Saipan, one has to do with the equipment at hand. An S1327A with VHF plug in.
I sucessfully retuned two Sinclair F201G hibred ring duplexers.
13DB desense to none measured.
I have managed to tune these critters with out the fancy toys, because they didn';t exist. I also found that 90deg elbows make fine cable stretchers for down banding Sinclair duplexers.
The early ones with soldered notch stubs can be tricky.
If you are in the business you should have modern test equipment, but for the odd project it is silly to spend several thousand for one or two
projects.
You dont have to know how to drive with a stick shift, or read an analog watch, start a fire, but it sure helps to master basic skills.
I recall that manual very well, along with the Motorola T1500 manual.
I have had to tune these duplexers with out all these fancy tracking generators because in the early '70s they were not commonly available.
The only one was in the enginering office in Honolulu.
I could not tell the coustomer to wait for 25 years or so for the proper equipment to become available.
On a mountain top on the island of Tinian in the Northeren Marianas Islands or on Navy Hill On Saipan, one has to do with the equipment at hand. An S1327A with VHF plug in.
I sucessfully retuned two Sinclair F201G hibred ring duplexers.
13DB desense to none measured.
I have managed to tune these critters with out the fancy toys, because they didn';t exist. I also found that 90deg elbows make fine cable stretchers for down banding Sinclair duplexers.
The early ones with soldered notch stubs can be tricky.
If you are in the business you should have modern test equipment, but for the odd project it is silly to spend several thousand for one or two
projects.
You dont have to know how to drive with a stick shift, or read an analog watch, start a fire, but it sure helps to master basic skills.
Aloha, Bernie
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RESCUE161
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Anybody else ever used one of these? I just bought one and was wondering what to expect out of it. Thanks!mancow wrote:Check out the ATTEN AT5011 series on ebay.
I don't see any right now but they are usually up there for about $800-$1200.
It's a new spectrum analyzer with built in tracking generator that goes to 1000 Mhz.
mancow
Scott
KE4FHH
Religion: Kills folks dead!
KE4FHH
Religion: Kills folks dead!
It's definitely all that I need. Having everything in one box is nice. Some say the user interface is horrible but I don't find it bad at all. Having a tracking generator can't be beat. I fumbled with a mini duplexer for ages before and never really used it because it was such a pain to try to tune with just basic stuff. With this thing I had it done if a few minutes.
The only thing that sucks is it's so huge and the fan is crazy loud.
The only thing that sucks is it's so huge and the fan is crazy loud.
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RESCUE161
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I think that one at the shop is an Agilent. I is VERY nice. I don't work there, but the guy was going into detail explaining everything to me as he was tuning one of my duplexers.
I got bitten by the damn Spectrum Analyzer Bug, so I hope it won't be as bad as when that Motorola Bug bit me...lol HOPEFULLY, the AT5011 will take care of me for a while as it's just for personal/HAM use.
I got bitten by the damn Spectrum Analyzer Bug, so I hope it won't be as bad as when that Motorola Bug bit me...lol HOPEFULLY, the AT5011 will take care of me for a while as it's just for personal/HAM use.
Scott
KE4FHH
Religion: Kills folks dead!
KE4FHH
Religion: Kills folks dead!
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RESCUE161
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Well, I got it today. Didn't take me too long to figure it out and only took me about 10 minutes to tune a duplexer and I was taking my time.
My thoughts. The frequency is not very stable - it only lists in 100 KHz steps and it jumps back and forth. It still works and does everything I need, but if you need precision, I'd hold off on this one.
I think a seperate signal generator would really make things easier, but those things are not cheap either.
So, if you are just using it for HAM use, this should work for you. I compare the one at the radio shop to a Rolls Royce and this one to Pinto. Yeah, the Pinto will get you from point A to B, but it's so much nicer to drive in style (safer too).
My thoughts. The frequency is not very stable - it only lists in 100 KHz steps and it jumps back and forth. It still works and does everything I need, but if you need precision, I'd hold off on this one.
I think a seperate signal generator would really make things easier, but those things are not cheap either.
So, if you are just using it for HAM use, this should work for you. I compare the one at the radio shop to a Rolls Royce and this one to Pinto. Yeah, the Pinto will get you from point A to B, but it's so much nicer to drive in style (safer too).
Scott
KE4FHH
Religion: Kills folks dead!
KE4FHH
Religion: Kills folks dead!
Tuning of duplexer
A service monitor or spectrum analyzer with tracking generator and a 50 ohm bridge, possibly Wiltron or Eagle. These bridges will let you see the VSWR of the cavities and final tuning will show little or no reflected power. Tuning by these bridges also will pad the test 50 ohms.
I think you mean "100 Hz steps", not 100 kHz steps. Otherwise either you are doing something terribly wrong or the unit is busted.RESCUE161 wrote: My thoughts. The frequency is not very stable - it only lists in 100 KHz steps and it jumps back and forth.
As for "jumps back and forth" - you may need to check to see if connecting an external 10 MHz reference fixes that - if so, the TCXO is bad.
This is my opinion, not Aeroflex's.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.