I recommend anyone wishing to understand HOW this type of filter works, to use Simsmith and model it. Very easy to do. Thanks Ape for the discussion of these filters. They sure can help 95% of most receivers as manufacturers seem to be skimping and cutting corners. 73 OM
I am impressed by the data. I test every filter and balun I purchase and recommend everyone do that. I paid twice as much for a different brand, tested them, returned them and was sent WORSE replacements, was ghosted, then bought from yet another brand and received perfect units on the first try (Hamation rocks!). After all my drama, I can now do 100w POTA with friends also doing 100w side by side
Home brew are often better than commercial stuff. They are trying to cut corners. We aren't. But ultimately, when we build our own we KNOW what we have and what it will do.
Great video. I used band pass filter from Morgan Systems in Salt Lake. There are some filter for AM Rejection too. I had that problem, an AM station too close to me and causing issues on 80m and 40 m. I got one of thier BCB filter and it cleared it up.
I build bandpass filters to include switchable filters I even have a few build videos. Don't use hot glue you will melt it and possibly start a fire. JB weld will change and certain resin epoxies will change your tuned SWR/VSWR. I use GC Electronics 10-3702 Q Dope,Pure Polystyrene Coating,Cement,Bottle with Brush,2 oz when I need to lock in my windings. As usual an enjoyable video.
@@TheSmokinApe Your welcome also on a BPF it doesn't matter which end you connect too antenna radio if it works it should be interchangeable but on this particular design do not tune through the filter you will blow the capacitors tune then attach the filter.
This was a very good effort to help us for multi- op use & tips to tighten up one inductor , w/ testing most of us cannot or will not do .Thank You for the Discount links , 73
Ape, I like your content. Especially your way of making the complicated easy to understand. I’ve been in the wireless industry for over 20years. I like the use of filters. We used to use them on spectrum analyzers when near out of band high power transmitters. Really lowers the noise floor. You should lone one to K8MRD to see how it affects his signal at his house. Might not help much but it could
Hey Tom, glad you liked the video and thank you for watching 👍. These are getting shipped out tomorrow for a buddy of mine who has been wanting to test them
I have a few of these ones for various bands, they are fantastic. I also have some low pass versions. They match the advertised specs very well (I have calibrated equipment to test them). Very cool!
I've been looking at these, but wasn't to sure. I was actually thinking of getting one or two and sending them to you to test. I have the equipment, but you know the tinySA better than I do. Thanks for the reviews. Makes me a little more confident. Once over postal strike is over I might get a few.
To really characterize real world performance, you need to look at the attenuation the 20 meter signal at the adjacent ham bands. In the case of the 20 meter filter, it is down a little over 30 dB at 18 MHz., a decent reduction, and it should be a lot better at 15 or 40 meters. I have experienced operating a 20 watt 20 meter station using a very similiar designed filter, and my 20 meter signal caused severe interference to a 17 meter station operating 200 feet away. The 17 meter station then moved to15 meters and all was well. In that instance, it may have been that the station on 17 meters could have stayed on 17 if he had been using a bandpass filter as well.
Also there is a 6m version. Its quite wide 48MHz to 60Mhz-ish at the -3dB points according to my nano VNA. A very useful bit of kit. Have you ever looked at the Rx path back through the filter? It should be reciprocal but sometimes I'm not sure.
Those filters are a good choice - most common ham bands. For listening outside ham bands, you could use a 30m filter - and check the 10MHz time signals from Hawaii / Colorado. These signals should be "close enough" to make it through the filter. Could also try a 15m filter, and 20MHz time signals.
You either had a bad cable or a lose connection when showing the NanoVNA the first time. But overal great and thanks for looking at the filters, I thought bout buying a set but wasn't sure about the true performance
Seeing the mildly lose components - my first thought was to forget the hot glue idea and use the Red Permatex. Stuff used to glue engine heating pads on the oil pan when you winterize your truck.
Great job testing . I was wondering on them . I only have 10 and 20 meter ones now. They let me work FT 8 on 2 bands same time from 2 radios and antennas' Lots of contacts ! I have band pass boards from DX world. Full legal power. multi band with 12V relays. I just need rotary switch,case and SO 239 . I do have one for CB coming but held up in bad weather.NY and many outher places getting winter storm and high winds . With good coax jumpers and good coax feed line you can easy overcome insertion loss . start with good 1/2 wave or 5/8 wave antenna that has great recieve. You won't even notice any loss from filters. That what I did. Them filters help with out of band noise . That can improve signal to noise ratio to help pull out weak station. 73
@@TheSmokinApe You can test with single port SWR sweep testers like the MFJ or Comet. use dummy load do a SWR sweep. Just gives a general reading of band pass frequency . Does not give attenuation DB data. This is where a VNA 2 port is really needed . I say more tools for the shack
Hello friend! Watching this video, I was reminded of the fact that BAOFENG HTs are "deaf" when connected to an external antenna. Could you explain to me the reason and a possible solution to this problem? Thank you very much! Greetings from Brazil!!
It’s because they use a direct conversion front end which goes a little haywire when subjected to strong signal. I rarely recommend someone upgrade to a higher gain antenna because of this 👍
Can you filter out RFI to drop the noise floor? Obviously not how a bandpass filter works. Think you could design an external filter for 40m that boosts the signal, maybe does some EQ, and filters the RFI?
Basically an attenuator which most radios have these days. They will also lower the signal you are trying to hear but hopefully improve the overall signal to noise ratio 👍
I would definitely glue those. They make a wicked white silicone glue that is used in electronics to glue everything like coils, capacitors, etc.They usually also glue the edges of the board in a few spots so it can't move either.
Interesting review. Yes 200W Digital modes would warm them up, as well as the transceiver driving them. 0.75 dB loss is about 32W/ 200W (16% loss) and 0.56 dB is about 24W/200W (12% loss). Never sure of the quality of the ferrites/Iron powder for some of the products.
Unboxing reviews, or promo nonsense reviews by people who don't understand anything about what they are reviewing. They are an irritating joke. But I have no problem with honest, thorough product reviews from knowledgeable hams. Especially if the reviews teach something about the product being reviewed, and even how to build your own. Your reviews are all of that. They are everything a good review can be, and are an important service to the community. They are the sort of thing that Elmers do. Ham radio is a hobby of learning. Most hams start out knowing very little about the hobby, and so buy stuff off the shelf in order to get started. Some never take it any further. That's OK, but they miss a whole lot. The rest continue on, learning how to set up a station, solve problems, build and tune their own antennas and accessories, repair and embellish their gear, and ultimately even build entire stations from junk-box parts, or do experimentation that can answer questions they have, or even push the hobby into the future. It's all up to the ham what they learn and what they do. You give them the understanding and option to do it all.
Amateur radio is not an hobby (thats golf, gardening, etc.) It is a tech and scientific personnal activity for the advancement of knowledge and tech skills. If it was an hobby, the governments would not spare hundreds of millions of dollars worth of radio frequency allocations. It's not a critic to you, sir. Just a simple comment. Your text is otherwise perfect. Congrats.
@paulsengupta971 Not really. That would be gardening etc. Radioamateur is meant as a non profit tech advancement activity. Otherwise hams would have to pay millions for the frequencies.... Don't give them ideas....😊😊
Thanks John. I agree, many HR videos now are someone trying to get you to click an affiliate link vs educate about HR... those are the same people doing videos about why ham radio is dying. I appreciate the kind words.
A bandpass filter for 3-30 MHz would be a bit much. What you may want is a _high pass filter_ that cuts off about 2 MHz or one that blocks the FM spectrum from 88-108 MHz. Stopping is likely to work better than passing.
There is a version of RTV like chemical which works for vibration in high temp environments. That would be my suggestion to support the coil. Thanks for the video Ape! 73
Would the 20m meter version of the band pass filter work to make the MX-P50M meet the FCC requirements? Of course it would require moving the BPF between the MX-P50M and the antenna. Thanks, I'm learning a lot from your videos! 73 KB3JC
One of my lecturers in university was Professor Butterworth, who I believe was the grandson of Stephen Butterworth who came up with the Butterworth filter.
If you live in a residential area and you get some interfirence that you cannot identify would this help in rejecting out of band signals to immprove your recieve reception?
Ham radio tube did a video last year in april 2023 called "how not to pota in the desert." In that video he was using these band pass filters and was getting a lot of blead through from hes buddy in a different band. Might be interesting to take a look at that.
Thanks for the review of these BPFs for the 40/20 m bands. The SWR is always compared to 1. At 10.05 and 12.30, by mistake you said like 1 to so and so. I am not nit picking but to be more of a pedantic. I love your presentation as always. De VU2RZA
Thanks for the info was looking at these for the club for extras. Band pass filters are expensive to only use twice a year but we run 7a for fd. So more are needed. 73 KA4FLA
Know where one could get reliable 2m and/or 70cm Band STOP filters? Like so you could have a scanner running and still use your dual band rig and not blow out the front end of the scanner?
The filters necessary depend on how much power you run on the ham bands, and how far apart the scanner antenna is from the ham antennas. Sometimes putting the scanner antenna 10 or 15 feet directly below a vertical colinear ham antenna is sufficient isolation to protect the front end of the scanner. It helps to carefully (use about a 30 dB attenuator inline,) monitor the scanner antenna with a spectrum analyzer like the TinySA to see how strong the 2 meter/70 cm signals actually are that would reach the scanner. Then you know how strong of a signal you need to attenuate, and how much the filter needs to attenuate it. In situations like that it helps to get an idea of what the filters actually have to do instead of just guessing and buying. As you pointed out, you want something reliable.
@ fair enough, that’s a good idea too. I don’t have a tinySA but I could look at getting one, unless my NanoVNA would work instead. Even if I was to do that I don’t know where to go looking for said band stop filters in the first place. Do you know of makes, models, dealers, stores, etc. that would sell them?
I ordered one a month ago for 80m band. I measured with Siglent and it showed -10dB on 3.5MHz and -2dB on 5.13MHz. i don't know if I'm doing something wrong with measurement, as the analyzer is new to me but that seems terrible. It showed the same in SA and VNA S21 mode, was normalized before measurement and was 0dB on straight cable. It's just so awful that I can't be sure I measure correctly.
I can't see what kind of capacitors are used. There has to be quality capacitors temperature stable and with good ESR value. And those are pricey... de LY5T
For those operating multi-band simultaneous operations during field day, these things are essential, especially for lower frequency stuff that may generate very small but very detectable harmonics on upper bands. An additional 20 or 30 dB of attenuation may make a very noticeable difference to the operator on the table next to you. As for securing the coils, may I suggest Q-Dope? If you don't know what that stuff is, here's a recipe: ua-cam.com/video/-_yJUdSBTHg/v-deo.html
I literally can’t watch half the content of the world woke web due to a cat allergy. What next… sponsored fur balls from AliExpress? Mein Furballs. In all seriousness though did those filters come in packages with the letters GmbH stamped on them? Recently anything ‘RF’ from them comes with the German abbreviation for ‘LLC’ hinting they’re made in Germany, when they’re not. An odd trend.
I recommend anyone wishing to understand HOW this type of filter works, to use Simsmith and model it. Very easy to do. Thanks Ape for the discussion of these filters. They sure can help 95% of most receivers as manufacturers seem to be skimping and cutting corners. 73 OM
Smithchart?
@@Charlie-Bee No. "Simsmith" (Google it)
Hey Hollywood, you are right about SimSmith. I should prolly do move videos using it... thanks for watching.
@@Charlie-Bee, that's the way we old-timers do it. We like to do things the hard way. :)
I am impressed by the data. I test every filter and balun I purchase and recommend everyone do that. I paid twice as much for a different brand, tested them, returned them and was sent WORSE replacements, was ghosted, then bought from yet another brand and received perfect units on the first try (Hamation rocks!).
After all my drama, I can now do 100w POTA with friends also doing 100w side by side
What was the good brand? 73
I'm also curious what brand he found that worked well.@@VE9ASN
Thanks for watching Brian 👍
Home brew are often better than commercial stuff. They are trying to cut corners. We aren't. But ultimately, when we build our own we KNOW what we have and what it will do.
Great video. I used band pass filter from Morgan Systems in Salt Lake. There are some filter for AM Rejection too. I had that problem, an AM station too close to me and causing issues on 80m and 40 m. I got one of thier BCB filter and it cleared it up.
I could have sworn I did a video on AM filters but now I can't find it 😡
it was The episode titled RTL-SDR filters. you showed both FM and AM filters.
@ that sounds about right
I build bandpass filters to include switchable filters I even have a few build videos. Don't use hot glue you will melt it and possibly start a fire. JB weld will change and certain resin epoxies will change your tuned SWR/VSWR. I use GC Electronics 10-3702 Q Dope,Pure Polystyrene Coating,Cement,Bottle with Brush,2 oz when I need to lock in my windings. As usual an enjoyable video.
Thats good info, thank you
@@TheSmokinApe Your welcome also on a BPF it doesn't matter which end you connect too antenna radio if it works it should be interchangeable but on this particular design do not tune through the filter you will blow the capacitors tune then attach the filter.
Thank You I appreciate the education on the filters.
@@ChuckBigbie glad you liked it Chuck, thanks for watching 👍
I just got 2 of them last week. So far so good. Took about 2 weeks to arrive.
@@ThinGrayLine nice, let us know how they work out for you
Your handle reminds me of my state LE. Any correlation?
If there was, I'd never admit it 😳
@@TheSmokinApewhy
Very cool Ape!!!
Chuck!
Nice review! You expressed the information in very clear terms. Great filters for field day like operations. Thank you for sharing.
Hey Bill, thanks for watching 👍
This was a very good effort to help us for multi- op use & tips to tighten up one inductor , w/ testing most of us cannot or will not do .Thank You for the Discount links , 73
You’re welcome, glad you found it helpful! 👍
these are pretty much a must-have for groups operating separate bands in a relatively close together area. it helps with crossband interference.
💯thanks for watching Richy 👍
Ape, I like your content. Especially your way of making the complicated easy to understand.
I’ve been in the wireless industry for over 20years. I like the use of filters. We used to use them on spectrum analyzers when near out of band high power transmitters. Really lowers the noise floor.
You should lone one to K8MRD to see how it affects his signal at his house. Might not help much but it could
Hey Tom, glad you liked the video and thank you for watching 👍. These are getting shipped out tomorrow for a buddy of mine who has been wanting to test them
I have a full set from 160m up to 2m I settled them all are in spec as Bandpass filters 73 brother great show
Awesome Andy, thanks for watching 👍
I have a few of these ones for various bands, they are fantastic. I also have some low pass versions. They match the advertised specs very well (I have calibrated equipment to test them). Very cool!
Thanks for the info, I like playing around with filters 👍
I've been looking at these, but wasn't to sure. I was actually thinking of getting one or two and sending them to you to test. I have the equipment, but you know the tinySA better than I do. Thanks for the reviews. Makes me a little more confident. Once over postal strike is over I might get a few.
Hey Steven, thanks for checking out the video 👍
To really characterize real world performance, you need to look at the attenuation the 20 meter signal at the adjacent ham bands. In the case of the 20 meter filter, it is down a little over 30 dB at 18 MHz., a decent reduction, and it should be a lot better at 15 or 40 meters. I have experienced operating a 20 watt 20 meter station using a very similiar designed filter, and my 20 meter signal caused severe interference to a 17 meter station operating 200 feet away. The 17 meter station then moved to15 meters and all was well. In that instance, it may have been that the station on 17 meters could have stayed on 17 if he had been using a bandpass filter as well.
The price had me skeptical, but your test results changed my mind!
Hey SF, thanks for watching 👍
Also there is a 6m version. Its quite wide 48MHz to 60Mhz-ish at the -3dB points according to my nano VNA. A very useful bit of kit. Have you ever looked at the Rx path back through the filter? It should be reciprocal but sometimes I'm not sure.
it should be the same both way but some I have seen are not.
Those filters are a good choice - most common ham bands.
For listening outside ham bands, you could use a 30m filter - and check the 10MHz time signals from Hawaii / Colorado. These signals should be "close enough" to make it through the filter.
Could also try a 15m filter, and 20MHz time signals.
They could come in handy for sure 👍
You either had a bad cable or a lose connection when showing the NanoVNA the first time. But overal great and thanks for looking at the filters, I thought bout buying a set but wasn't sure about the true performance
Hey John, one of the Sma’s was loose, good eyes 👀
Seeing the mildly lose components - my first thought was to forget the hot glue idea and use the Red Permatex. Stuff used to glue engine heating pads on the oil pan when you winterize your truck.
Not a bad idea, someone else mentioned JB Weld
Thanks ape. Do they do better than coax stubs? Would like to see a field video of how well they do
I haven’t used stubs, sorry man. I’m sending these to a buddy for winter field day. When I get them back I can do more testing 👍
Great job testing . I was wondering on them . I only have 10 and 20 meter ones now. They let me work FT 8 on 2 bands same time from 2 radios and antennas' Lots of contacts ! I have band pass boards from DX world. Full legal power. multi band with 12V relays. I just need rotary switch,case and SO 239 . I do have one for CB coming but held up in bad weather.NY and many outher places getting winter storm and high winds . With good coax jumpers and good coax feed line you can easy overcome insertion loss . start with good 1/2 wave or 5/8 wave antenna that has great recieve. You won't even notice any loss from filters. That what I did. Them filters help with out of band noise . That can improve signal to noise ratio to help pull out weak station. 73
Hey Robert. I agree with you BPFs can make a big difference, thanks for watching!
@@TheSmokinApe You can test with single port SWR sweep testers like the MFJ or Comet. use dummy load do a SWR sweep. Just gives a general reading of band pass frequency . Does not give attenuation DB data. This is where a VNA 2 port is really needed . I say more tools for the shack
@ that’s a handy tip 👍
Hello friend!
Watching this video, I was reminded of the fact that BAOFENG HTs are "deaf" when connected to an external antenna. Could you explain to me the reason and a possible solution to this problem? Thank you very much! Greetings from Brazil!!
It’s because they use a direct conversion front end which goes a little haywire when subjected to strong signal. I rarely recommend someone upgrade to a higher gain antenna because of this 👍
@TheSmokinApe I got it! You rock man! Thanks!
@ 👍
Can you filter out RFI to drop the noise floor? Obviously not how a bandpass filter works. Think you could design an external filter for 40m that boosts the signal, maybe does some EQ, and filters the RFI?
Basically an attenuator which most radios have these days. They will also lower the signal you are trying to hear but hopefully improve the overall signal to noise ratio 👍
I would definitely glue those. They make a wicked white silicone glue that is used in electronics to glue everything like coils, capacitors, etc.They usually also glue the edges of the board in a few spots so it can't move either.
@@bruceweight7319 that’s probably the right thing to do
Interesting review. Yes 200W Digital modes would warm them up, as well as the transceiver driving them. 0.75 dB loss is about 32W/ 200W (16% loss) and 0.56 dB is about 24W/200W (12% loss). Never sure of the quality of the ferrites/Iron powder for some of the products.
Hey technishn, agreed. Thanks for doing the maths!
Unboxing reviews, or promo nonsense reviews by people who don't understand anything about what they are reviewing. They are an irritating joke. But I have no problem with honest, thorough product reviews from knowledgeable hams. Especially if the reviews teach something about the product being reviewed, and even how to build your own. Your reviews are all of that. They are everything a good review can be, and are an important service to the community. They are the sort of thing that Elmers do.
Ham radio is a hobby of learning. Most hams start out knowing very little about the hobby, and so buy stuff off the shelf in order to get started. Some never take it any further. That's OK, but they miss a whole lot. The rest continue on, learning how to set up a station, solve problems, build and tune their own antennas and accessories, repair and embellish their gear, and ultimately even build entire stations from junk-box parts, or do experimentation that can answer questions they have, or even push the hobby into the future. It's all up to the ham what they learn and what they do. You give them the understanding and option to do it all.
Amateur radio is not an hobby (thats golf, gardening, etc.)
It is a tech and scientific personnal activity for the advancement of knowledge and tech skills.
If it was an hobby, the governments would not spare hundreds of millions of dollars worth of radio frequency allocations.
It's not a critic to you, sir.
Just a simple comment.
Your text is otherwise perfect. Congrats.
@@jplacido9999 It's a hobby. A tech hobby for the advancement of knowledge and tech skills.
@paulsengupta971
Not really.
That would be gardening etc.
Radioamateur is meant as a non profit tech advancement activity.
Otherwise hams would have to pay millions for the frequencies....
Don't give them ideas....😊😊
Thanks John. I agree, many HR videos now are someone trying to get you to click an affiliate link vs educate about HR... those are the same people doing videos about why ham radio is dying. I appreciate the kind words.
Very well done. Could you please do a video on a broadcast bandpass filter. Possibly a home brew model for 100 watts, plus or minus.
Thanks
A bandpass filter for 3-30 MHz would be a bit much. What you may want is a _high pass filter_ that cuts off about 2 MHz or one that blocks the FM spectrum from 88-108 MHz. Stopping is likely to work better than passing.
I cover them here but will do more filter videos in the future: ua-cam.com/video/zT1_T25rg3g/v-deo.html
Can you show your handmade filter on the Nano VNA for comparison??
It’s the first video in the playlist in the description 👍
There is a version of RTV like chemical which works for vibration in high temp environments. That would be my suggestion to support the coil. Thanks for the video Ape! 73
Thanks for the idea 💡
But will it work with an ATAS120?
Will it help with noise from a portable generator?
We tried to work mobile from a parade last night 😞
They will work with the ATAS and they MIGHT help with the generator noise 👍
Would the 20m meter version of the band pass filter work to make the MX-P50M meet the FCC requirements? Of course it would require moving the BPF between the MX-P50M and the antenna. Thanks, I'm learning a lot from your videos! 73 KB3JC
I didn’t test it, but I am sure it would 👍
One of my lecturers in university was Professor Butterworth, who I believe was the grandson of Stephen Butterworth who came up with the Butterworth filter.
@@paulsengupta971 that’s awesome 👍
Did you saturate them with power to determine if the work under load?
I did not
@ I was curious only because of my own Bandpass experiences have given me poor results after I super heated the toe-roid.
@ it’s a fair point and question
If you live in a residential area and you get some interfirence that you cannot identify would this help in rejecting out of band signals to immprove your recieve reception?
@@ChuckBigbie yes
@TheSmokinApe thank you just ordered 4 of them
@ let us know how they work for you 👍
Ham radio tube did a video last year in april 2023 called "how not to pota in the desert." In that video he was using these band pass filters and was getting a lot of blead through from hes buddy in a different band. Might be interesting to take a look at that.
I'll have to check that out! Thanks for the tip! 👍
Thanks for the review of these BPFs for the 40/20 m bands.
The SWR is always compared to 1.
At 10.05 and 12.30, by mistake you said like 1 to so and so.
I am not nit picking but to be more of a pedantic.
I love your presentation as always.
De VU2RZA
Hey VU2RZA, thanks for catching that! Glad you liked the video!
@@TheSmokinApe yes, I liked it very much. Thank you for your prompt response 👍 😀
De VU2RZA
Thanks for the info was looking at these for the club for extras. Band pass filters are expensive to only use twice a year but we run 7a for fd. So more are needed.
73
KA4FLA
Hey Chuck, I agree that hey can get pricey for that!
@TheSmokinApe tnx for the great video.
Know where one could get reliable 2m and/or 70cm Band STOP filters? Like so you could have a scanner running and still use your dual band rig and not blow out the front end of the scanner?
The filters necessary depend on how much power you run on the ham bands, and how far apart the scanner antenna is from the ham antennas. Sometimes putting the scanner antenna 10 or 15 feet directly below a vertical colinear ham antenna is sufficient isolation to protect the front end of the scanner. It helps to carefully (use about a 30 dB attenuator inline,) monitor the scanner antenna with a spectrum analyzer like the TinySA to see how strong the 2 meter/70 cm signals actually are that would reach the scanner. Then you know how strong of a signal you need to attenuate, and how much the filter needs to attenuate it. In situations like that it helps to get an idea of what the filters actually have to do instead of just guessing and buying. As you pointed out, you want something reliable.
@ fair enough, that’s a good idea too. I don’t have a tinySA but I could look at getting one, unless my NanoVNA would work instead. Even if I was to do that I don’t know where to go looking for said band stop filters in the first place. Do you know of makes, models, dealers, stores, etc. that would sell them?
Rather than hot glue you might use one of the epoxies made by J-B Weld. They're strong and can handle the heat.
I like that idea 💡
I ordered one a month ago for 80m band. I measured with Siglent and it showed -10dB on 3.5MHz and -2dB on 5.13MHz. i don't know if I'm doing something wrong with measurement, as the analyzer is new to me but that seems terrible. It showed the same in SA and VNA S21 mode, was normalized before measurement and was 0dB on straight cable. It's just so awful that I can't be sure I measure correctly.
@@pangalacticgargolblaster9578 have you measured other filters and gotten the expected results?
@@TheSmokinApe No, I only had this one. I sent it back today. It was the same housing and internal structure sold as 3.52 MHz BPF.
Luckily for you, Ape, I ❤ my cats videos but I came back to watch the rest of your video. 😂🤣
Haha, thanks man 👍
Yes, the bandwidth is 2.4 Mhz, the SWR is
Thanks
I can't see what kind of capacitors are used. There has to be quality capacitors temperature stable and with good ESR value. And those are pricey... de LY5T
I’m right here and I can barely see them 👀
Sweet
Thanks 👍
For those operating multi-band simultaneous operations during field day, these things are essential, especially for lower frequency stuff that may generate very small but very detectable harmonics on upper bands. An additional 20 or 30 dB of attenuation may make a very noticeable difference to the operator on the table next to you. As for securing the coils, may I suggest Q-Dope? If you don't know what that stuff is, here's a recipe: ua-cam.com/video/-_yJUdSBTHg/v-deo.html
Thanks for the link 👍
Thanks Ape!! After watching your videos, then I go watch cat videos...hi hi. 🤣
I get it, sometimes you just need a break from ham radio lol
How dare you assume my critter watching habits sir 🤣
lol
Indeed, the video I watched before this was a dog video!
ha
The word 'either' is not a synonym for 'each'.
Thank you so much, I will sleep better tonight knowing that…
Why Am I hearing this in a foreign language I do not speak? There is no way to change it to English!!
I kinda speak English
I literally can’t watch half the content of the world woke web due to a cat allergy.
What next… sponsored fur balls from AliExpress?
Mein Furballs.
In all seriousness though did those filters come in packages with the letters GmbH stamped on them?
Recently anything ‘RF’ from them comes with the German abbreviation for ‘LLC’ hinting they’re made in Germany, when they’re not. An odd trend.
No packages, just wrapped in bubble wrap and no lettering