Excellent! Been years since I tuned a Duplexer!

Great explanation of duplexors. Excellent tutorial!

@TRXLab

7 жыл бұрын

Glad that you liked it. Thank you 73

Very detailed video which is very helpful thanks again Peter

Great video, explained in great detail

I like your videos.Very professional and informative.Keep up the good work buddy ! Have a good day.

@TRXLab

7 жыл бұрын

Thank you glad that you liked it 73

Fantastic video Peter, as always!!!

@TRXLab

7 жыл бұрын

Thank you Mauricio. 73

thank you for the informative video about the duplexer. well done.

@TRXLab

6 жыл бұрын

glad that you liked it 73

exellent as ever looking forward to many more..cheers peter.

@TRXLab

7 жыл бұрын

Thanks for feed-back 73

Great video as always ,thank you Peter

@TRXLab

7 жыл бұрын

Always glad to see you Dennis. Thank you 73

Congratulations! Great video explanation! much clear and pointfull!

@TRXLab

6 жыл бұрын

Glad that you liked it 73

Thank you so much, now I understand more about spectrum analyzers, to use tracking generator and cavity filter or duplexers. Amazing in one video you teach and share a lot of knowledge material, hope you are always healthy and blessed 🙏🏿

Thanks for another great video Peter! I had a duplexer like that on my old Regency repeater. No idea what I did with it. Brought back a lot of memories with that one lol. Have a good day and take care. 73 Buddy

@mikesradiorepair

7 жыл бұрын

The Radio Shop It's buried in a pile somewhere. You'll find it when you need it the least. Look for it and you'll never find it. :-)

@TRXLab

7 жыл бұрын

Thank you Buddy, yeah I have seen you diy video very good stuff. Take care my friend 73

@TRXLab

7 жыл бұрын

Yeah Mike never try to find what you need :^)

Great information on the subject clear and understandble.

@TRXLab

5 жыл бұрын

Thanks for feed-back Patrick.

I think it is fascinating to watch a spectrum analyzer while a filter is being adjusted, and see what each adjustment actually does to the attenuation spectrum!

@TRXLab

7 жыл бұрын

Yes I agree a vector network analyser is something amazing. 73

thank you for sharing so more information!

@TRXLab

7 жыл бұрын

Thanks John 73

When adjusting a duplex filter, you must connect a 50 ohm termination to the port that is open, and after adjustment you must use a SWR bridge to get the correct point where the filter has its optimal and lowest SWR still with 50 ohm termination on the open port..

@srdjanstanojevic4287

5 жыл бұрын

Can you please explain SWR bridge? How do you do that? Thanks for the answer.

@andhanwer

4 жыл бұрын

correct on terminating the other port properly, it wasn't done here ! simply adjusting for deepest nulls and lowest loss is insufficient without considering return loss also all these multiple rf connector adapters are highly inappropriate another serious consideration is lengths of the coax - ignored here as well poor job this repeater will work like crap

@tedfrisk4730

3 жыл бұрын

@@srdjanstanojevic4287 With a SWR bridge you get a much greater dynamics and resolution as well as a better control of the impedance in the selected frequency that you intend to tune the filter to, I recommend a very good page about tuning Duplexer and the difference between using SWR bridge, look at W2AEW's site he is tuning with both ways, 73 the SM4PDP

i hope yopu do vhf pre amp projects for repeater use, love you videos

Excellent video! 73 de SM4VFA

Another great video by Peter. Excellent. Peter, can you do a video on folded dipoles for VHF or UHF base station repeater antenna.

@TRXLab

7 жыл бұрын

Thank you Allen! Sorry I don't have the stuff to do a antenna video....

Peter, i agree with some of the other comments: The unused open port had not been terminated with a 50 Ohm load. Most, if not all duplexers need ALL the ports terminated during the tune up process as the unconnected port is still in circuit, despite not being "part" of the tune up circuit! Especially true with the small cavity multi-port duplexers that were originally designed for mobile use! Having said that, great video Peter and hope the new repeater is on air as we speak! Continue with the super work, 73, Brian EI8EJB

@TRXLab

7 жыл бұрын

Hi Brian, yes you are right but as you said MOST duplexers needs to be terminated. This type is not vulnerable to it. I have tested it before with and without termination and no difference. In our final test we had both ports terminated tidily and our pre calculated and finally measured results are completely matching. But I see that I should have shown it with both termination loads simply not to confuse viewers and to teach what always is the right way and not what will only work partly. Thanks for comment 73

@brianwhelan5093

7 жыл бұрын

Wonderful reply Peter and I hope that you did not take my comment as a negative criticism; this was not my plan!! You have forgotten more electronics theory than most (including myself) will ever learn in a life time Peter! Alles gute! 73... :)

@TRXLab

7 жыл бұрын

Ah,,... no the repeater is not yet up. I have to work on the receiver as well. Hope I can do a video on crystal temperature stabilisation...

@TRXLab

7 жыл бұрын

No No don't worry Brian I'm not superman an do fail as anybody else....

@brianwhelan5093

7 жыл бұрын

You are too modest Peter! Looking forward to the next video and thanks as always for the detailed and very interesting videos!

On most duplexer connections, isn't the high connection used for receiving the signal and the Low connection used for transmitting the signal. Assuming the repeater receives on the high frequency and transmits on the low frequency?

You are tuning a duplexer without a dummy load on the other end of the filter LOL. Good luck with the performance of it.

@pixeluser8243

3 жыл бұрын

If I were you, I would technically and socially be careful in choosing my words to Peter.

@leosedf

3 жыл бұрын

@@pixeluser8243 you amateurs amaze me all the time

@pixeluser8243

3 жыл бұрын

@@leosedf Bring your girl and she'll be too.

@leosedf

3 жыл бұрын

@@pixeluser8243 I wouldn't expect any other reply from an idiot amateur like you. Now go tune a duplexer without a load lol

Great video Peter! I have often combined these flat pack notch duplexers with additional cavity filters to help with out of band performance, essential for RF busy comms sites. One quick question, what equipment are you using for the spectrum analyser and tracking generator?

@TRXLab

7 жыл бұрын

You are right you can improve the performance that way. Thanks for watching Michael 73

I like your accent. Love the video.

Interesting. 7.6 MHz offset? I figured it would be 5. Almost any amateur radio automatically adjusts for a 5 MHz offset. New info for me. Great video and got some great knowledge watching this. Keep them coming. 73, ad0am

@Drekkag

7 жыл бұрын

Forgot, you are in a different country. that explains the 7.6 offset. sorry

@TRXLab

7 жыл бұрын

Yes that is the answer, Adam...Thanks for watching 73

Great video as always Peter. Thank you for the efforts. Would like to ask what result have to expect if leave the notch and pass frequency little bit missaligned, but match the VSWR more close to 1:1. In other words, which is better: To keep notch not so deep (let say LF at -60dB and HF at -80 or -70dB) and VSWR close to 1:1. New ham here TA1OSN, Ferit. Respect and 73!

@TRXLab

5 жыл бұрын

-70 to-80 is a good result so go ahead if you have a good VSWR! 73

Peter, congratulations for your work! What Spectrum Analyzer do you used in this video? Thank you! 73`s, Chris, YO8RZE

If any public safety LMR folk are watching and reading.... especially if you handle QC2 2-tone sequential paging / DTMF station alerting / etc... Check out the TPI-1005a RF communications device.... It has just about everything in a single package to permit local transmissions of alerting tones etc.. and RF (CW) signal & function generation all in a very affordable (aka cheap - $200-300 bucks?) package. A few KZread videos have been done on the device, so check them out if you have a spare sec.

Haha!! I've tuned many of those in my time!!

@TRXLab

7 жыл бұрын

Yes that is pure fun 73

I am interested which can-adjustment does what to the notch or the bandpass, even if it is wishy.

@TRX Lab would you be kind to let me know what software and hardware you have you are using in this video to tune? I like how this one is setup and the hardware under monitor.

Thank you so much. Can you do video tunning duplexer with nanovna?

@va3vad

4 жыл бұрын

I would like to see that.

Hallo Peter, schön gemacht! Richtig lustig wird es bei den 2m Duplexern mit 600kHz Breite..Da habe ich schon eine Kaskade von "Ölfässern" gesehen, die man mit der 1/2 Zoll Ratsche abstimmen musste;-) Gruß und 73 de Olaf, DK6KF Nice Work, Peter! Another funny thing is to do the alignment to 2m band duplex filters with 600 kHz bandwith. I have seen a "cluster of oilbarrels" that needed to be aligned with a 1/2" ratchet ;)

@TRXLab

7 жыл бұрын

Vielen Dank Olaf, ja da gibt es die wildesten Konstruktionen...., aber der hier ist echt handzahm :^) Danke fürs vorbeischauen. 73

@OleF112

7 жыл бұрын

Peter, ich schaue schon von Video 42 an zu...;-) und arbeite mich noch rückwärts. Macht Spass! PS: Falls Du mal Teile aus dem kommerziellen Bereich brauchst, habe viele Ersatzteile zum Spenden..Ich arbeite gerne mit Bosch, Ascom und Motorola.

@TRXLab

7 жыл бұрын

Freut mich das es dir so gut gefällt, Olaf...Auch vielen Dank für das Angebot man weiß nie was man braucht. Ich komme gerne darauf zurück. 73

why there is not dummy load on open port?

Probably should have a 50ohm dummy load on the open port.

I have a question can a 25 watt repeater handle a 30 watt duplexer or will I have to go at low power

Another great video, I have never seen a duplexer being calibrated before, so it was fun for me. So, amateurs in Germany are allowed to use 12.5 KHz steps in Germany? We are still stuck with 25 KHz here in Turkey.... :(

@TRXLab

7 жыл бұрын

Thank you Bora. Yes 12,5 is allowed...73

Hello, I'm wanting to setup a personal use repeater, Can I use the MX-72 Duplexer to do it? I see the one that you are using is setup high at 438.100 Mhz and low side is 430.500 on the J-unoda duplexer can you do the same with the MX-72 Duplexer? Sorry for the question, I'm new to ham radio. Or how can it be setup using the MX-72 Duplexer. I'm wanting to set it up as a GMRS repeater. I'm wanting to use just 1 antenna if possible. Thanks.

Question: Can I run a 5w receive radio on one port and a 50 watt transmit on the second port? (Lets assume this duplexer is rated for 100watts)

I have 2 VHF Motorola GM300s with a jumper cable on the back which makes the unit a repeater. I run 2 antennas for the Rx and Tx. I would like to run only 1 antenna. Can I purchase a duplexer, have it tuned and get rid of the jumper cable? Also, do I have to have a repeater controller just to make the GM300s and duplexer work? I would like to get by without using a controller.

The high mhz side for transmitting and the low mhz for receiving please let me know im confused and learning

What is inside the Duplexer cans? PI/PI-L networks? (I don't know anything about these) SWR: I would think that 1.5 swr would start to matter @ 440? Thanks, 73

@TRXLab

7 жыл бұрын

Hi Bud there are many different concepts how this can be achieved. The best is to google it as it is far to much to answer it all here...Sorry mate. Thanks for watching 73

@k5azebud988

7 жыл бұрын

Surprisingly there is little information about what is exactly inside, I only found one example, it was a cavity filter which to me a basically a notch filter. So apparently there is nothing exotic going on inside them...

@englisharcher5919

6 жыл бұрын

K5AZE Bud not much inside. There is some element (like the other end of that tuning rod) which effectively alters the physical dimensions of the cavity favoring only certain electromagnetic oscillatory modes. It is very much like the wineglass filled with different amounts of liquid resonating at only certain (audio) frequencies.

O.K......! Now I'm really confused ! Another video showed the opposite of how this video described the ports of the duplexer. Here he says that the High side is for the transmitter ? Another video I watched, claimed you should use the Low port for the transmitter ? Who is correct ? Or are the ports interchangeable, as long as you, the Tech/Operator understand how you designate each port ? 🤔....?

You'd have to terminate the terminals not used for measurement with 50 ohms.

Just one doubt..it's possibile to use both of inputs at the same time using a single antenna with a duplexer !? Thank you for your commitment !! '73 :)

@systemloc

7 жыл бұрын

Exactly. One is used for recieve, and one for transmit, at the same time. This is the purpose of a duplexer. It allows a repeater to recieve on one frequency and re-transmit the signal simultaneously

@alessandrozax

7 жыл бұрын

is it also possible to use both of input on TX at the same time !?

Why do you have the other unused port unterminated? I see people terminate the unused port

Please give some more informations about your measure equipment. What kind of analyser you use? Brand ? Model?

@TRXLab

3 жыл бұрын

in video #77 you'll find the answer...

Will the transmitter desensitized the receiver at -50dbm?

@TRXLab

6 жыл бұрын

If a signal is coming in on the "wrong" frequency it will be attenuated by the filter depth of the filter and if the filter depth is 50 dB yes it will be attenuated by 50dB

Can HIGH port transmit as LOW port?

not really clear on video if your tuning the high side do you loosen all six ? the high side has 3 adjustments and the low side has 3 adjustments?

@TRXLab

Жыл бұрын

This is an iterative setting so you move all the controls over and over again

Uhf can be vhf?

Flat packs should only be used in portable repeaters.

What VNA are you using?

@TRXLab

7 жыл бұрын

Hi, watch video #77 and/or #106. There you get all needed informations. Thanks for watching. 73

Peter was benutzt du als Spectrum Analyser?

@TRXLab

5 жыл бұрын

Hallo Andre, schau mal mein Video #77 dort werden alle Fragen beantwortet

@andreneumann9781

5 жыл бұрын

Peter hast du schon mal einen ICOM 718 in der Hand gehabt und du die RX Werte eingestellt?

why cant we just use a switch to disconnect between transmit and receive?

@michaelcarey

7 жыл бұрын

A duplexer is needed in a repeater because the transmitter needs to be active at the same time as the receiver into the one antenna. You can use separate antennas for transmit and receive, but you would still need to have some kind of filtering to keep the transmitter energy out of the receiver antenna socket. Two antennas also means two coax cable runs and often more running costs if you are leasing space on a tower.

@harbselectronicslab3551

7 жыл бұрын

because it you do that it is no longer Duplex......you need to be able to TX and RX at the same time with a repeater.

@justcasey3678

7 жыл бұрын

This is one antenna repeater system for both tx and rx. The receive signal is needed to pass thru the duplexer and go to the receiver, and at the same time the information is transmitting thru the same antenna. As Peter pointed out, the duplexer will notch out the tx frequency signal at the rx port. If a switch is used while transmit, then the receiver will not be connected to the antenna to receive any signal.

only problema here is you need used 50ohm in port duplexer for adjust you figure for tracking generetor no is good you need setting with 50ohm terminal 73 Raul

@TRXLab

7 жыл бұрын

This topic has already discussed here in the threat down below.. Thanks for watching 73

Too much talk..next time just tell wharts that thing use for

@TRXLab

5 жыл бұрын

easy don't watch it :-)

great video but you made fatal error, you didn't terminate the unused port so results are meaningless!

@TRXLab

7 жыл бұрын

Nick, do you really think we could get our final result as we have seen it if my approach if it is a fatal error? All pre calculated and finally measured results are completely matching. At the finial test both ports were terminated... So my results are meaningless? Are you sure? Thanks for watching 73

@nickphilpot420

7 жыл бұрын

hi thanks for replying, I really enjoy your videos & appreciate the time & energy that goes into making them, hope my comment didn't cause offence! Best wishes nick

@TRXLab

7 жыл бұрын

No No don' worry I'm always open for discussions. Have a nice day 73

This was so long and boring I had to skip through it. Was there a part where he showed how he trimmed the duplexer? I mean the physical box.

He must get paid per word or something. I can't take it any more! 3 minute of actual usable teaching and 47 minutes of "yeah", "um" and word salad.

taking too much time to explain :(