Can These Cheap Ali Express Band Pass Filters Be Any Good??

Рет қаралды 9,377

8 ай бұрын

We're Testing HF Band Pass Filters From Ali Express On The NanoVNA. They're Very Inexpensive But How Good Can They Be?
★Links chosen at random. There are many different "sellers" so you may want to look around a little bit before purchasing. There are also other bands available. I have absolutely no affiliation whatsoever with Ali Express so buy at your own risk. I assume no responsibility.
7MHz: www.aliexpress.us/item/325680...
14MHz: www.aliexpress.us/item/325680...
18MHz: www.aliexpress.us/item/325680...
21MHz: www.aliexpress.us/item/225183...
28MHz: www.aliexpress.us/item/325680...
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Пікірлер: 52

@hacker08 8 ай бұрын

cool to see tom segura is a ham

@PendejoRyan 8 ай бұрын

I get that a lot. Either Tom Segura or the cop from Stranger things. I don't know whether either or a compliment or an insult 😂

@fyrearm 8 ай бұрын

Thanks for this video, been looking for other options for band-passes. Few of us like doing POTA together and this will help. I have a few ICE bandpass filters from RandL, they run about $74 and work. I might pick one of these up and see how they compare.

@jameski5oeb668 8 ай бұрын

I have the Butterworth BPFs made for winter field day this year. The ones from QST a few decades back don’t work QRO, they are designed to be place between the transceiver and the amplifier. Go read the for page instructions and you’ll understand what I had to learn the hard way over the weekend. They quickly saturate with heat at 100 watts SSB. Then the SWR curve won’t come down, similar to 100w FT8 into a 49:1 Toe Roid on an EFHW… so run power Mike just put the BPF between the radio and the AMP, then run 10w or so to the amp. Your mileage may vary! Good luck Mike!

@KM4ACK 8 ай бұрын

Good info. Thanks Mike!

@hamradiotube 8 ай бұрын

You bet!

@carypeaden4147 Ай бұрын

Very useful. Thanks.

@wildbill1 8 ай бұрын

Awesome for that price going to have to order some

@don_n5skt 8 ай бұрын

The pentaplexors and the old BPF that DX Engineering had were from Low Band Systems out of Europe. They do still exist and are selling on their website. I do have some of the ones from DXE but would love to pick up some others. Will check these out. Thanks.

@eljam8138 4 ай бұрын

I think this is what i need for my HackRF SDR !

@Philip-KA4KOE 8 ай бұрын

Good stuff.

@arnoldgrubbs2005 8 ай бұрын

Thanks for showing these, I had not thought to look on Ali. I wonder if you could do another vid and measure how many dB of rejection for the adjacent bands the filter has? Also the harmonic related bands, such as what you would see on your Rx on 7.1 MHz if someone was on 3.550 MHz? Again, thanks!

@robertmeyer4744 8 ай бұрын

them some nice filters. 200 watt. should do 100 watt FT8 no problem . if you push too much power the ferrite heats up and SWR climes up just like ferrite does on antenna's. each person needs to have a filter for the band they want to use. 6 meters with 80,160 meters is far away may not bother each outher so much but depends on the radio rejection out of band. 73's

@krisraps 21 күн бұрын

I "Love" How You Say They Are "Cheap" For Me They Are Most Expensive Filters, I Don`t own One Because i Cant Afford One.

@technishn 8 ай бұрын

Look economically priced. I assume insertion losses were fractions of a dB. One could use a infrared thermometer to check temperature. The cases look like they are anodised. Hopefully the grounding is good.

@chriscoel 8 ай бұрын

Grabbed a 17M one, since there are billions of plans/instructions for the non-warc bands. These are easily half the price of even some of the cheaper ones. If they can isolate my diopole from the other guys BSP or Dipole.. I'll take it.

@speedymartin2 8 ай бұрын

Thanks! Would be good to know how you use all filters at the same time on a multiband antenna using one transceiver. Is a lot of work to swap them out regularly. 73’ PD1MV

@hamradiotube 8 ай бұрын

I literally just covered that on Monday's video. You need a Pentaplexer or Triplexer after the band pass filters.

@JonathanKayne 8 ай бұрын

I feel like bandpass filters are the type of thing that should be homebrewed. They are pretty simple to construct and make a great easy project for anyone. Plus there are tons of tools for designing filters on the Internet!

@Screamingtut 8 ай бұрын

Mike, so tell me something, with say using the 20-meter bandpass, it will reject all frequencies but 20 meters? I'm I correct in saying that!!!. PS I love it when you say you don't know everything, put I try. I used to know all this stuff 30 yrs ago. but hitting 70 sometimes the mine goes wandering sometimes.

@hamradiotube 8 ай бұрын

that is correct

@va3hie 5 ай бұрын

Sounds good but I would like to know what the rejection is in db. If it's only 6 or 7 db of rejection, is that enough for what you want to do? More rejection is better. Not criticizing your work just wanting to know.

@blugoose86 8 ай бұрын

Hey Mike, will you and your friend do a vid on the setting up the Nano to test these filters? I'm on a hard fixed income and can't afford to buy a set of these filters, even though they look amazing simple to build. I have a low pass filter that covers 10-80, has relays and diodes and controlled by Arduino. I'm not sure if I tested them right and want to make sure before I add the high pass portion. Thanks, and as usual, great video and solid information. de James KA9TII

@pale_2111 8 ай бұрын

Do they make a multiband pass filter instead of buying filters for each band? Having to buy a bunch of filter and changing them at home or out in the field would suck. I like to band hop at home and having something like a multiband pass filter would help out a lot.

@hamradiotube 8 ай бұрын

That would completely defeat the purpose of a band pass filter.

@tonyreneeLaszlo 8 ай бұрын

What was the attenuation in dB? Not sure if you have the S11 log mag setup on the nano VNA. 73, W4BMX

@PendejoRyan 8 ай бұрын

The blue line was the logmag

@feeatlastfeeatlast5283 8 ай бұрын

Your measurements concentrated on the match (SWR). The purpose is to reject frequencies outside the passband, so how much DO they reject other bands? The data is right there on the nano but hard to see on the video.

@PendejoRyan 8 ай бұрын

You are correct. We mentioned the blue LOGMAG signal on a couple of occasions during the video. I was actually looking at both the SWR and the LOGMAG to determine when the signal would be attenuated. Maybe if Mike has me on in the future and we do a more in depth look, we can explain it it more detail. It was a spur of the moment thing and I am not a KZfaqr , so you'll have to forgive me. I tried to make the explanation as simple as I possibly could so someone unfamiliar with band pass filters could get a basic understanding on what is occurring.

@yaobing-qw4rj 4 ай бұрын

Customized duplexers, filters, LC filters, power dividers, dual channel filters, design Negotiate prices based on indicators

@franksouter3939 2 ай бұрын

Thanks for the recommendation. Just got mine delivered today. One question? Where is best to have it inline? Before swr meter or after it?

@hamradiotube 2 ай бұрын

Not sure. I don't use an SWR meter. You'll have to experiment. I don't think it really maters though. I just put it close to my radio with a little 2' jumper and then out to the antenna.

@franksouter3939 2 ай бұрын

@@hamradiotube thanks. i'll just have a play and see what works best. Cheers dude

@larrynathanson9892 8 ай бұрын

TWINS!

@mikemcdonald5147 4 ай бұрын

guys look like twins with the bald heads and beards LOL thought you were gonna say im here with my brother. :)

@bradkellison5359 8 ай бұрын

End fed antennas are only out of Phase if you butt the feed points and slope the end of the wire away from the feed point. like the letter V with feed points at the bottom.

@hamradiotube 8 ай бұрын

I didn't say anything about phasing but they sure were interfering with each other.

@rayslinky 8 ай бұрын

haha, i was just wondering if one off aliexpress would be ok...

@yuabonuga 8 ай бұрын

What about 1.5-30mhz one?

@JonathanKayne 8 ай бұрын

That's what a low pass filter would be used for. If you wanted a 1.5-30MHz BPF you are basically wasting your money since it wouldn't do anything for you. These filters are useful for rejection of signals that would likely overload the front end of your transceiver. If you are operating on 20 meters and your friend is operating 40 meters a few dozen feet away then these are great.

@EvgeniX. Ай бұрын

I doubt nanoVNA measures even any reliable, considering those filters rated to 200w (which I also doubt) they can behave Very differently under real load vs the few milliwatts at the test bench ❌

@lhorschler 8 ай бұрын

Unapologetically Chinese lol, I love it

@EvgeniX. Ай бұрын

yeah that was spot on!

@pedrocatalan9814 8 ай бұрын

Twins?..

@PendejoRyan 8 ай бұрын

If it was Twins, he's Danny DeVito and I'm Arnold Schwarzenegger.

@hamradiotube 8 ай бұрын

See, he got the good stuff, I got the bad.

@PendejoRyan 8 ай бұрын

@@hamradiotubewait, are you saying I'm the shit leftover?

@laszlokovacs8827 8 ай бұрын

Definitely not twins, but I'd bet they use the same barber.

@startobytes 6 ай бұрын

40 and 50 bucks is not cheap tho

@PaulReedy 5 ай бұрын

It is compared to the ones you'll find from most suppliers. Figure out what bands you'll be operating the most and start buying one here & there till you have a full set for the price of one name brand one.