Have not thought about it. It sounds like work, YT is a more enjoyable platform for me to express my ideas or experience through videos. I feel I get more info across a visual "show me" method than a 2 dimensional media like writing. Bottom line, I have to have fun doing it. Thanks for watching
The Decibel Dupl was actually a BP/BR duplexer, it had a built in Capacitor to adjust the notch/band reject. Unfair comparison, but its was all I had at the moment.
I agree with Steve Wright. All I wanted to know in viewing this is what the insertion loss (mentioned), split (mentioned) and rejection (not mentioned, but somewhat readable in the video - see further comments). The comparison between a BR duplexer with a BPBR duplexer wasn't of much value. The rejection spec on these are typically -75 dB but I can't tell from this video if the device achieves the specified performance. It appears that the input signal is already attenuated and the measured rejection may be at the noise limit of the spectrum analyzer (the notch is at -95 dB with the reference signal at -40 dB, a rejection of only -55 dB). -35 dB rejection would be extremely bad. Unfortunately, I cannot determine if it is worth investing in one of these (my application would be a low power full duplex DMR hot-spot, where -75 dB rejection on a 5 MHz split is probably adequate. Sorry, but this video left me wanting. If this video were re-done with a higher reference signal that enabled the rejection to be measured, there would be great value in having that information.
I just have a question. I got one of these and my repeater TX is 462.675 and my RX is 467.675. I told the company to program the high to the 467 and the low to the 462. Am I correct?
I'm here because I bought a Fumei duplexer. I can get it to reject the opposing frequencies, but the desense on the receiving radio makes the repeater range shorter than just using an HT simplex.
we are using one of these in uhf band at a mountain top ( 8500 Ft). we have noticed that there is a loss in rx signal as compared to 2 antennas however it works fine till 110 miles with a 5 watt handy. cant complain given the pricing and its performance. ideal for where 2 antennas cant be installed. on the other hand we have a sinclair full size duplexer on vhf setup installed at the same location and thats a breeze but costs a fortune.
I have a db products 450 - 470 duplexer similar to the one you show here. I got it as part of ham repeater. The SWR is high on the tx side 443, have you ever tried tuning a 450 to 470 down to 443/448?
Sorry for the delay. The duplexer will work, its the frequency and antenna used that will be impacted by environment. There's debate which band works best, VHF and UHF are neck & neck. VHF travels farther with less power but UHF penetrates and travels in tight spaces due to its smaller wave length. the duplexer should work fine in a non radio congested site.
Don't know whee to find answer.. Working on a stealth repeater in my head. Want to put everything in a 4" sewer drain pipe, camoflage it, Could slip out to a ridge, and plant it, have a couple sticks for a 20' pole, small solar cell like yours attached towards the top. Can one of these notchers be taken apart to be two units or stacked so fit inside a 4" pipe? Thanks.
I may be wrong, but I think you could buy another cheap duplexer, flip it over the opposite direction and put it in line and use high pass on low and low pass on high and combined together you could make the 2 sets like this I to a bandpass if I have my thinking straight. I don't know how much additional loss you are going to get, but it may be a cheap but not impossible way to help keep interference to you and from you down. DCI also makes some bandpass....or did anyway...that a friend used a lot to help keep things a bit better off.
It's a notch filter, not a bandpass/notch-reject filter like your large cans, and you are right to say this is not suitable for co-siting with other radio equipment.
@@lancelotxavier9084 This notch-plexer is already designed to reject the transmit frequency of the repeater. What you could do is install a band pass filter that will only let the receive frequency pass through. The only problem is it will create more dB/signal loss.
@@lancelotxavier9084 you can add a band pass cavity in between the receiver and this duplexer, along with another on the tx side. Note that your insertion loss goes up.
Have you thought about authoring an ebook on amazon? A good basic explanation of some principles and some possible SHTF ideas for comms and etc? Thanks!
Dont worry, it was unloaded, safety was in full effect and control. I did not have a similar filter to compare the chinese notch model so I used a bandpass notch to show somthing similar. Most of my viewers are new to this, so I try to show as much contrast and examples that I can with a little fun on the side. Thanks for watching and your concern.
This is a notch filter aka a mobile duplexer. It doesn’t filter out any other out of band sources like a BpBr Band pass band reject duplexer. The BpBr is the type of duplexer you would use at repeater tower site.
We have seen cheap Russian/Ukraine, somewhere in that area, duplexers very similar to these tune up nicely but fail shortly after operational power is applied. By operational power, I mean 25-50 watts. And shortly may be a month to a year. At that point you can retune the transmit side, but as soon as power is applied it will immediately fail. Has anyone noticed that with the Chinese duplexers?
In the UK many base stations use the small duplexers.... barrels are often used in communal aerial systems where many transmitters and receivers are sharing one aerial. The barrel filters are so selective that they can be a problem with extremes of temperature.
You are absolutely right, and I totally agree. Unfortunately those Ebay chinese duplexers are vague in their description and it has prevented me from buying one. Now we know for sure what they are all about. the comparison I admitted was unfair apples to oranges but it was just to show the differences between them. Thanks for watching..
I have one of the Chinese duplexers, mine had 3dB loss which is not even close to specs. I have a Celwave US made duplexer that the Chinese copied to make the cheap ones you see on eBay. The Celwave brand met specs. If you look closely on eBay they show a 10mhz frequency spread. In the US normal UHF repeaters operate with a 5mhz frequency spread. The narrower the spread the worse the Chinese models perform. Who knows how they will stand up to temperature changes. A good quality duplexer like the Bandpass/Bandreject duplexer you have is very stable in hot and cold temperatures. The metal that makes up the tuning rods must be stable, not grow or shrink with temperature or the critical tuning will change.
Im actually considering buying a Chinese 220 mhz 1.6 mhz split notch duplexer. Planning on putting it in the freezer and then testing drift. That and i can use it as a rough guide to rebuild it better.
Just to be correct, the mobile duplexer you tested is a reject only duplexer. The receiver side rejects it own transmitter and the transmitter side rejects its own receiver frequency.
That's bad, those contacts must be arcing when power runs through them. Another reason to stick to reputable manufacturers. The cost in frustration and monetary will pay for good quality equipment, especially when used in emergency purposes. thanks for the input & watching.
Intriguing at first until you learn that most from China on Ebay etc. specify a much wider minimum freq. separation than we typically use in the U.S. Quality duplexers provide about 80-85dB attenuation between high and low. Check this before you buy.
Do you know the IC2730a Icom? I want to turn something into a mobile repeater. I'm looking for something to use in my Jeep for when I go hiking with my baofeng and my Jeep buddies. I'm looking at an IC2730a but I'm looking for someone to guide me. I'm a newbie.
Just as a note.. most people testing these say you may get upto a 75khz drift.. meaning the 462.625mhz 'side' would pass 462.550mhz upto 462.700mhz. Not necessarily a bad thing if you need to switch a channel or two from you original planned frequencies.. obviously staying on your frequency listed on the duplexer would be best for best results.. as always YMMV.. (I do own one of these with 2 Motorola 40w units.. works great for my usage..) I also run 1/2 Heliax wire to reduce 'noise' as well.. though my LMR400 type cable worked well for over 4 months before I opted for the Heliax.
Yeah. But the lmr400 can be an issue in 5 years when the dissimilar metals corrode inside on the shield. Whereas 1/2" is good for 20 or 30 years from what I've seen in the field. That and you have much better shielding as you stated.
Do you know of a low wattage duplexer? I'm building a SHTF duplex repeater system using handhelds, but I really need to find a light-weight and small duplexer for VHF.
Ordered two of these from a Chinese manufacturer. Did not get around to using them for a few months and when I did they were badly tuned. A friend (40+ years of mobile radio experience) attempted to tune them and found the best he could get was 4db loss. Could not get them to tune properly at all. Compare that to the Cellwave mobile duplexer and no comparison. Cellwave tunes great. Of course seller would not honor warranty because it was only 30 days. Another lesson learned the expensive way. Maybe these are cheap knockoffs or they are seconds. Either way buyer beware.
+Bruce Wayne Yes it could. As long as there is no to minimal receiver desensitization. Duplexers biggest advantage is using less physical space on a tower where its at a premium.
I used those kind of duplexers back in the day they were much easier to find and full sized ones were expensive used. even the Phelps Dodge or Celwave ones are lossy about 3db compared to a real duplexer at 1.5 db.If you aren't colocated with 5 or 10 repeaters and are running less then 50 watts they work well in a pinch.
I got one on a gmrs repeater on a silo 36 air miles away. With all the trees and foliage around, it seems to kick ass. Although its a db or a sinclair.
Guerillacomm 1st Thanks for all of the time and effort you put into filming, editing and producing this channel. I am new to alot of this and look forward weekly to whats coming up as I learn alot from your shows. 2nd.. Quick question I just ordered one of these for a GMRS repeater I am setting up here. Does it matter what length my coax lines are coming from my radios (mini uhf) to the duplexer (N Connector) using LMR400? Thanks again for your time and effort to help those of us who are learning.
Richard Simmons Thanks for the kind words and congrats on your project. would like to know the details since whenever I have the $, would probably upgrade myself & I'm curious. Rule of thumb, engineers like to cut their cables on the exact wavelength or harmonic of the wavelength of the frequency you're using. especially on long runs of cable. On duplexers, their is a thing called critical length, but usually configured for complex antenna systems. For your setup, your components are top notch for the UHF band using LMR-400 & N-channel connectors, really efficient for UHF. I would say cut as short as possible and the critical length rule is negligible IMHO. I'm not an engineers as a disclaimer. Dont remember if mini uhf is efficient for higher frequencies, but I do know you need to check them often for tightness, I find those to come loose more than any other connectors I've messed with. Hope that helps and good luck on your repeater, thats awesome.
GUERRILLACOMM your welcome and again thanks for bringing knowledge, understanding, and excitement through your channel. I know i have learned alot and continue to in each video! Thanks as well on the congrats on the project. I will definitely share the details with you. Thanks a ton for the direction on the cable lengths and the mini uhf connectors coming loose alot. What's the best way to communicate the project details back to you? Thanks again!
+surplusdriller1 It will only block and filter out those frequencies. It just depend on your operating habits. Your operating procedure will determine how to configure the device. You will need test equipment to adjust the duplexer or cavities. Sometime in the future I will cover those procedures in detail.
This is WHY I NEVER buy Chinese core components for radio system. Portable are fine but as far as repeaters and such I stick with main brands. The small duplexer is a 50 watt where you big one is 100 + watts? I have a 10 watt (I think so dont quote me on that) UHF duplexer that I pulled from an old site repeater a few years back mounted 40 feet up on a utility pole. It was hooked to a pair of Motorola HT440's with a small simple controller and all housed in a weather proof box, with a 12V battery, Small solar panel and charge controller. It's tuned to 452.2375 / 457.2375 MHz and belonged to the local power company before they went on 800MHz EDACS.
The reason the waveforms are different is you are comparing a notch type mobile duplexer against a BpBr duplexer. The differences have nothing to do with being country of manufacture. It's like comparing apples to oranges. A good comparison would be to take a DB Products notch duplexer against the Chinese duplexer. Motorola uses the notch type duplexers in a lot of the smaller repeater systems. Like you said, the notch type duplexers are okay for low RF environments, but BpBr is better.
The Gaofeng I ordered has batteries that don't even fit into the radio !! Thankfully I also ordered a Yaesu, cost 6x as much though. Thanks for the review. There is a Ford (actually a Lincoln) I like you to test with your very fine fully automatic tester. No need to return it. Use it to run over Mark Fields (CEO).
That is too technical. I was expecting something like how is it powered, actual demonstration on how it really works and how will you program the frequency tx and rx. Can it be used with cats
Yes the mobile duplexers are notch only. I have found the Celwave mobile versions work better than the Chinese. I've seen the Chinese just not give enough isolation, they are on the edge. For mobile duplexers I now only get used Celwave or other American manuf. Also one needs to plug one into a repeater and not just look at on a spec anal. Is good video, but could have cut down to half without the extras, hi. Maybe do video on tuning both a mobile type and then base larger BP/BR type. And yes one needs to tune the duplexer to the exact tx and rx frequencies for the notches are rather narrow.
You are trying to compare two different designs and saying chinese one is crap, but actually see that chinese duplexer is doing exactly what it should do, so I know now it is not better or worse than US made of the same type.
it's a reject (notch) filter not pass reject . it only rejects (dumps as the author puts it) the opposite frequency. They are junk for any type of rf environment. Chinese or USA the second set is MUCH better as far as filter.
Thanks for the update, was a bit worried since YT has been messing with accounts in various ways. Keep safe! I am learning programming for the XTL5000, a real learning curve! 73!
You're completely comparing two different animals, you should compare duplexer packs from China and the United States what you're doing there is comparing a 50 watt duplexer pack to a high power duplexer can
OMG....Has a little kid running around in the background and a rifle sat on the table. Gun safety 1.01 obviously passed you by. And the reason that the Chinese filter is different to the "American" made one is because they're two completely different types of filter - not that one is Chinese and the other American.
Why did you delete my comment, I asked you if you worked for PSC and which shop. believe me I know who are you, one phone call and email with your YT video link to HQ will make you out.
+t95mwp I don't know who you are and I keep my info private for obvious reasons not related to work. I have nothing to hide from HQ, just from anonymous individuals here on YT that could show up at my door. That's why I deleted your comment, too much info, should of sent a PM. As far as the Div, its no secret, many know and there is nothing in my content that discredits the organization, if anything, it promotes it in subtle ways. If you really know who I am, then you should know my reputation with-in the organization is very high and no non-sense.
Have not thought about it. It sounds like work, YT is a more enjoyable platform for me to express my ideas or experience through videos. I feel I get more info across a visual "show me" method than a 2 dimensional media like writing. Bottom line, I have to have fun doing it. Thanks for watching
The Decibel Dupl was actually a BP/BR duplexer, it had a built in Capacitor to adjust the notch/band reject. Unfair comparison, but its was all I had at the moment.
I agree with Steve Wright. All I wanted to know in viewing this is what the insertion loss (mentioned), split (mentioned) and rejection (not mentioned, but somewhat readable in the video - see further comments). The comparison between a BR duplexer with a BPBR duplexer wasn't of much value. The rejection spec on these are typically -75 dB but I can't tell from this video if the device achieves the specified performance. It appears that the input signal is already attenuated and the measured rejection may be at the noise limit of the spectrum analyzer (the notch is at -95 dB with the reference signal at -40 dB, a rejection of only -55 dB). -35 dB rejection would be extremely bad. Unfortunately, I cannot determine if it is worth investing in one of these (my application would be a low power full duplex DMR hot-spot, where -75 dB rejection on a 5 MHz split is probably adequate. Sorry, but this video left me wanting. If this video were re-done with a higher reference signal that enabled the rejection to be measured, there would be great value in having that information.
I just have a question. I got one of these and my repeater TX is 462.675 and my RX is 467.675. I told the company to program the high to the 467 and the low to the 462. Am I correct?
Yes, you're correct. Sounds good to me. Have fun with your project...
I'm here because I bought a Fumei duplexer. I can get it to reject the opposing frequencies, but the desense on the receiving radio makes the repeater range shorter than just using an HT simplex.
we are using one of these in uhf band at a mountain top ( 8500 Ft). we have noticed that there is a loss in rx signal as compared to 2 antennas however it works fine till 110 miles with a 5 watt handy. cant complain given the pricing and its performance. ideal for where 2 antennas cant be installed. on the other hand we have a sinclair full size duplexer on vhf setup installed at the same location and thats a breeze but costs a fortune.
I have a db products 450 - 470 duplexer similar to the one you show here. I got it as part of ham repeater. The SWR is high on the tx side 443, have you ever tried tuning a 450 to 470 down to 443/448?
Sorry for the delay. The duplexer will work, its the frequency and antenna used that will be impacted by environment. There's debate which band works best, VHF and UHF are neck & neck. VHF travels farther with less power but UHF penetrates and travels in tight spaces due to its smaller wave length. the duplexer should work fine in a non radio congested site.
Don't know whee to find answer..
Working on a stealth repeater in my head.
Want to put everything in a 4" sewer drain pipe, camoflage it,
Could slip out to a ridge, and plant it, have a couple sticks for a 20'
pole, small solar cell like yours attached towards the top.
Can one of these notchers be taken apart to be two units or stacked so fit inside a 4" pipe?
Thanks.
I may be wrong, but I think you could buy another cheap duplexer, flip it over the opposite direction and put it in line and use high pass on low and low pass on high and combined together you could make the 2 sets like this I to a bandpass if I have my thinking straight. I don't know how much additional loss you are going to get, but it may be a cheap but not impossible way to help keep interference to you and from you down. DCI also makes some bandpass....or did anyway...that a friend used a lot to help keep things a bit better off.
It's a notch filter, not a bandpass/notch-reject filter like your large cans, and you are right to say this is not suitable for co-siting with other radio equipment.
can a second duplexer be put in serial to the receiving end to block a chunck of frequency opposite of the transmitting frequency?
@@lancelotxavier9084 This notch-plexer is already designed to reject the transmit frequency of the repeater. What you could do is install a band pass filter that will only let the receive frequency pass through. The only problem is it will create more dB/signal loss.
@@lancelotxavier9084 you can add a band pass cavity in between the receiver and this duplexer, along with another on the tx side. Note that your insertion loss goes up.
Have you thought about authoring an ebook on amazon? A good basic explanation of some principles and some possible SHTF ideas for comms and etc? Thanks!
Dont worry, it was unloaded, safety was in full effect and control. I did not have a similar filter to compare the chinese notch model so I used a bandpass notch to show somthing similar. Most of my viewers are new to this, so I try to show as much contrast and examples that I can with a little fun on the side. Thanks for watching and your concern.
I loved the ar15 cameo joke. 🤣🤣🤣
This is a notch filter aka a mobile duplexer.
It doesn’t filter out any other out of band sources like a BpBr Band pass band reject duplexer.
The BpBr is the type of duplexer you would use at repeater tower site.
We have seen cheap Russian/Ukraine, somewhere in that area, duplexers very similar to these tune up nicely but fail shortly after operational power is applied. By operational power, I mean 25-50 watts. And shortly may be a month to a year. At that point you can retune the transmit side, but as soon as power is applied it will immediately fail. Has anyone noticed that with the Chinese duplexers?
In the UK many base stations use the small duplexers.... barrels are often used in communal aerial systems where many transmitters and receivers are sharing one aerial. The barrel filters are so selective that they can be a problem with extremes of temperature.
Not terribly common on base radios here, but we do actually do that on repeaters as well. Its a combiner setup
@@nicklikesradio I did not mean "base station" in the often used ham way. Sorry for the confusion.
You are absolutely right, and I totally agree. Unfortunately those Ebay chinese duplexers are vague in their description and it has prevented me from buying one. Now we know for sure what they are all about. the comparison I admitted was unfair apples to oranges but it was just to show the differences between them. Thanks for watching..
I have one of the Chinese duplexers, mine had 3dB loss which is not even close to specs. I have a Celwave US made duplexer that the Chinese copied to make the cheap ones you see on eBay. The Celwave brand met specs. If you look closely on eBay they show a 10mhz frequency spread. In the US normal UHF repeaters operate with a 5mhz frequency spread. The narrower the spread the worse the Chinese models perform. Who knows how they will stand up to temperature changes. A good quality duplexer like the Bandpass/Bandreject duplexer you have is very stable in hot and cold temperatures. The metal that makes up the tuning rods must be stable, not grow or shrink with temperature or the critical tuning will change.
Im actually considering buying a Chinese 220 mhz 1.6 mhz split notch duplexer. Planning on putting it in the freezer and then testing drift. That and i can use it as a rough guide to rebuild it better.
Just to be correct, the mobile duplexer you tested is a reject only duplexer. The receiver side rejects it own transmitter and the transmitter side rejects its own receiver frequency.
That's bad, those contacts must be arcing when power runs through them. Another reason to stick to reputable manufacturers. The cost in frustration and monetary will pay for good quality equipment, especially when used in emergency purposes. thanks for the input & watching.
Intriguing at first until you learn that most from China on Ebay etc. specify a much wider minimum freq. separation than we typically use in the U.S. Quality duplexers provide about 80-85dB attenuation between high and low. Check this before you buy.
Do you know the IC2730a Icom? I want to turn something into a mobile repeater.
I'm looking for something to use in my Jeep for when I go hiking with my baofeng and my Jeep buddies.
I'm looking at an IC2730a but I'm looking for someone to guide me. I'm a newbie.
Just as a note.. most people testing these say you may get upto a 75khz drift.. meaning the 462.625mhz 'side' would pass 462.550mhz upto 462.700mhz. Not necessarily a bad thing if you need to switch a channel or two from you original planned frequencies.. obviously staying on your frequency listed on the duplexer would be best for best results.. as always YMMV.. (I do own one of these with 2 Motorola 40w units.. works great for my usage..) I also run 1/2 Heliax wire to reduce 'noise' as well.. though my LMR400 type cable worked well for over 4 months before I opted for the Heliax.
Yeah. But the lmr400 can be an issue in 5 years when the dissimilar metals corrode inside on the shield. Whereas 1/2" is good for 20 or 30 years from what I've seen in the field. That and you have much better shielding as you stated.
Copy that, its all I had to compare the differences. Thanks for watching.
Do you know of a low wattage duplexer? I'm building a SHTF duplex repeater system using handhelds, but I really need to find a light-weight and small duplexer for VHF.
Ordered two of these from a Chinese manufacturer. Did not get around to using them for a few months and when I did they were badly tuned. A friend (40+ years of mobile radio experience) attempted to tune them and found the best he could get was 4db loss. Could not get them to tune properly at all. Compare that to the Cellwave mobile duplexer and no comparison. Cellwave tunes great. Of course seller would not honor warranty because it was only 30 days. Another lesson learned the expensive way. Maybe these are cheap knockoffs or they are seconds. Either way buyer beware.
been looking at these myself...have to see what kinda work comes up if I order one or not
Instead of using a duplexer, could moving one of the antennas 17' > away, be a more cost effective solution?
+Bruce Wayne Yes it could. As long as there is no to minimal receiver desensitization. Duplexers biggest advantage is using less physical space on a tower where its at a premium.
GUERRILLACOMM Thank you GC...
I used those kind of duplexers back in the day they were much easier to find and full sized ones were expensive used. even the Phelps Dodge or Celwave ones are lossy about 3db compared to a real duplexer at 1.5 db.If you aren't colocated with 5 or 10 repeaters and are running less then 50 watts they work well in a pinch.
I got one on a gmrs repeater on a silo 36 air miles away. With all the trees and foliage around, it seems to kick ass. Although its a db or a sinclair.
Its not designed as a bandpass filter. The price you pay for a 1/4 wave duplexer is no where near what you would pay for the commercial duplexer.
GG, would these cheap duplexers work satisfactory out in a pine field with no other radios around?
Is there a way i can get ahold of you?
+Matthew Babb PM's only. I don't get personal on YT unless the person has a YT presence that's not too out there.
It is almost sweeping like a cable TV trunk amp diplex filter.
Good comparisons, as I've been considering the China made. Now I'll be looking at older American made. Thanks
Guerillacomm 1st Thanks for all of the time and effort you put into filming, editing and producing this channel. I am new to alot of this and look forward weekly to whats coming up as I learn alot from your shows. 2nd.. Quick question I just ordered one of these for a GMRS repeater I am setting up here. Does it matter what length my coax lines are coming from my radios (mini uhf) to the duplexer (N Connector) using LMR400? Thanks again for your time and effort to help those of us who are learning.
Richard Simmons Thanks for the kind words and congrats on your project. would like to know the details since whenever I have the $, would probably upgrade myself & I'm curious. Rule of thumb, engineers like to cut their cables on the exact wavelength or harmonic of the wavelength of the frequency you're using. especially on long runs of cable. On duplexers, their is a thing called critical length, but usually configured for complex antenna systems. For your setup, your components are top notch for the UHF band using LMR-400 & N-channel connectors, really efficient for UHF. I would say cut as short as possible and the critical length rule is negligible IMHO. I'm not an engineers as a disclaimer. Dont remember if mini uhf is efficient for higher frequencies, but I do know you need to check them often for tightness, I find those to come loose more than any other connectors I've messed with. Hope that helps and good luck on your repeater, thats awesome.
GUERRILLACOMM your welcome and again thanks for bringing knowledge, understanding, and excitement through your channel. I know i have learned alot and continue to in each video! Thanks as well on the congrats on the project. I will definitely share the details with you. Thanks a ton for the direction on the cable lengths and the mini uhf connectors coming loose alot. What's the best way to communicate the project details back to you? Thanks again!
Richard Simmons PM's are fine. Thanks for sharing.
Not a cheap but nice duplexer! I would like to have a couple Decibel duplexers. Nice spectrum analyzer too!
Great review, it help me to understand what is a duplexer and how it works. Hope to more of this type of reviews. Thanks
Can i use this to jamme, scramble and block everything in the 380-385Mhz TETRA band if not how can i do it?
+surplusdriller1 It will only block and filter out those frequencies. It just depend on your operating habits. Your operating procedure will determine how to configure the device. You will need test equipment to adjust the duplexer or cavities. Sometime in the future I will cover those procedures in detail.
Looks like the Chinese duplexer is a notch/band-reject duplexer and your U.S. unit is a band pass duplexer.
This is WHY I NEVER buy Chinese core components for radio system. Portable are fine but as far as repeaters and such I stick with main brands.
The small duplexer is a 50 watt where you big one is 100 + watts?
I have a 10 watt (I think so dont quote me on that) UHF duplexer that I pulled from an old site repeater a few years back mounted 40 feet up on a utility pole. It was hooked to a pair of Motorola HT440's with a small simple controller and all housed in a weather proof box, with a 12V battery, Small solar panel and charge controller.
It's tuned to 452.2375 / 457.2375 MHz and belonged to the local power company before they went on 800MHz EDACS.
Thanks for keeping us informed.
Great video well done would your first name be Joe by chance? Just curious let me know thank you again.
No sir, the closest Joe to me is my brother in law... Thanks for watching, take care.
Thanks for the video, greetings from Veracruz, México
The reason the waveforms are different is you are comparing a notch type mobile duplexer against a BpBr duplexer. The differences have nothing to do with being country of manufacture. It's like comparing apples to oranges. A good comparison would be to take a DB Products notch duplexer against the Chinese duplexer. Motorola uses the notch type duplexers in a lot of the smaller repeater systems. Like you said, the notch type duplexers are okay for low RF environments, but BpBr is better.
comparing a notch duplexer to a Bp/Br is not fair.
That was my first thought as well. Fair comparison would have been RFS notch duplexer VS Chinese notch duplexer.
Another good vid...keep up the good work!
The specs say they are narrowband.
Outstanding GC.
You are not clear.
Poor performance because its made in China or poor performance due to the compact size or both?
Normal performance for this type of duplexer. Nothing to do with made in China. US made duplexer of the same type would show exactly same graph.
The Gaofeng I ordered has batteries that don't even fit into the radio !! Thankfully I also ordered a Yaesu, cost 6x as much though.
Thanks for the review.
There is a Ford (actually a Lincoln) I like you to test with your very fine fully automatic tester. No need to return it. Use it to run over Mark Fields (CEO).
That is too technical. I was expecting something like how is it powered, actual demonstration on how it really works and how will you program the frequency tx and rx. Can it be used with cats
Yes the mobile duplexers are notch only. I have found the Celwave mobile versions work better than the Chinese. I've seen the Chinese just not give enough isolation, they are on the edge. For mobile duplexers I now only get used Celwave or other American manuf. Also one needs to plug one into a repeater and not just look at on a spec anal. Is good video, but could have cut down to half without the extras, hi. Maybe do video on tuning both a mobile type and then base larger BP/BR type. And yes one needs to tune the duplexer to the exact tx and rx frequencies for the notches are rather narrow.
You are trying to compare two different designs and saying chinese one is crap, but actually see that chinese duplexer is doing exactly what it should do, so I know now it is not better or worse than US made of the same type.
Ya, because someone will break into your home or bunker and target your duplexer before live threats.
it's a reject (notch) filter not pass reject . it only rejects (dumps as the author puts it) the opposite frequency. They are junk for any type of rf environment. Chinese or USA
the second set is MUCH better as far as filter.
Are you OK? Where have you been hiding? New platform?
Still around, just unmotivated and learning instead of teaching. have some ideas and projects, just slow at it. Thanks for the support.
Thanks for the update, was a bit worried since YT has been messing with accounts in various ways. Keep safe! I am learning programming for the XTL5000, a real learning curve!
73!
You're completely comparing two different animals, you should compare duplexer packs from China and the United States what you're doing there is comparing a 50 watt duplexer pack to a high power duplexer can
Interference not too much to worry about ? Ehh... any interference is bad! hence why you use a Tuned duplexer...
OMG....Has a little kid running around in the background and a rifle sat on the table. Gun safety 1.01 obviously passed you by.
And the reason that the Chinese filter is different to the "American" made one is because they're two completely different types of filter - not that one is Chinese and the other American.
50 WATTS MAX YOU CAN PUT INTO IT NO MORE THEN 50 WATTS I WAS GOING TO BUY ONE I NEED ONE THAT CAN HANDLE AT LEAST 200 WATTS
Why did you delete my comment, I asked you if you worked for PSC and which shop. believe me I know who are you, one phone call and email with your YT video link to HQ will make you out.
+t95mwp I don't know who you are and I keep my info private for obvious reasons not related to work. I have nothing to hide from HQ, just from anonymous individuals here on YT that could show up at my door. That's why I deleted your comment, too much info, should of sent a PM. As far as the Div, its no secret, many know and there is nothing in my content that discredits the organization, if anything, it promotes it in subtle ways. If you really know who I am, then you should know my reputation with-in the organization is very high and no non-sense.
1st 1 min, LMAO!!!
Lol