A Homemade Helical Bandpass Filter for the Two-Metre Amateur Radio Band

[@CerealKiller187]

Well done, Tony. Thank you for taking the time to make this video and sharing it with all of us.

[@EI5EM]

You are welccome. Thank you for your feedback.

[@mcturan]

Its a great example like a lesson to show people the antenna actually is important as much as the rig. If the person living inside a metropol like me, actually an antenna with filter is more important than what's the device. Thanks alot.

[@EI5EM]

Thank you.

[@johnc3403]

Wow! Brendan went from fully quietening to no discernable signal! That's the best example of de-sensing that I've seen and that filter works a treat. Well done Tony. John EI5JS

[@roy-wn3f]

Fantastic video! My very first SOTA activation was of Great Sugar Loaf EI/IE-022 nearby and I look forward to activating another peak or two in the area on my next visit

[@thedmutz]

Excellent video. Thanks for sharing how your built your filter. Pictures/video are worth a thousand words

[@acestudioscouk-Ace-G0ACE]

Thanks for this detailed build, I might try one!

[@krisraps]

WOW, WHAT A DIFERENCE, I NEED THAT FILTER !

[@EI5EM]

Thanks

[@W1RMD]

That's proof enough! Thanks and 73's!

[@EI5EM]

It may not look pretty but it works well.

[@IrishHamRadio]

That’s unreal Tony! Well done💪🏻💪🏻. The proof was definitely in that pudding😊. I need to make one of those for SOTA ops on Truskmore.

[@EI5EM]

The results were really dramatic and beyond my wildest expectations.

[@IrishHamRadio]

@@EI5EM Yep unreal how you could hear literally nothing without the filter. I knew desensing existed, but that was quite dramatic in the way you demonstrated it. It removes all doubt of the benefit of the BPF. Really cool.

[@milekokotov1964]

Well done Tony. I am glad that you are satisfied with the results. It`s a very nice and effective VHF band pass filter which is easy to build. 73 de Z33T

[@EI5EM]

Thanks so much Mile for commenting on my build and a particular thanks for sharing the design. My build is not pretty and I hadn't PCB panels large enough so I had to join halves. It's magical how it works and my video demonstrates it very well. Thanks again Mile and best 73 from Ireland de Tony (EI5EM).

[@over-engineered]

I have an Icom IC-V80E 2m only handheld radio, and I was shocked to find it could stand being connected to the aerial on top of a ham repeater tower - next to a commercial site. This was about 12 years ago when there was still quite a lot of active commercial equipment on the tower including cellular, pagers, trunked band 3 PMR with continuous transmitting control channel.

[@SteveWithnell]

Nice demonstration!

[@whiskersandhoppersbackyard2504]

Well done sir. This has been helpful for our repeaters here in the philippines. Thank you for sharing sir. 73

[@EI5EM]

You are very welcome

[@EI5EM]

I operated as DU1/EI5EM from Cainta, Rizal recently on CW HF. But local QRN was over S9. So I had to abandon it.

[@hzgl]

Well done! I’ll take some inspiration from this and see if they’ll help with the RF interference problem in my apartment.

[@EI5EM]

Best of luck. It's only for 2m that it blocks other RF signals out of band.

[@maxasaurus3008]

Damn impressive Sir, wild difference indeed! I need a pen…. Thank You!

[@tomaszmaniak1187]

Well done, this filter is great .EI9IDB

[@EI5EM]

Mni tnx

[@MakeDoAndMend1]

Hi Tony . Really good. I need a similiar one to this for the UHF band 70cm. Suffering from interference from arials on a water tower near my home. But haven't any idea how to make one. Cheers from old George in the UK 🇬🇧

[@EI5EM]

Thanks George. It really performed beyond my expectations.

[@dz-abouttechnique1849]

Nice video!

[@terencespross]

I plan on building the filter for the opposite problem: Instead of interference on receive, I have a Radtel rt-470x ht that is good except in has atrocious 2nd harmonic suppression on transmit and I don't want to interfere with anybody our of band.

[@EI5EM]

Good luck with it.

[@WafaAz-Zuhri]

the Mile Kokotov schematic are using copper plate 32mm, so can we use a PSB for replacement for it? i see your is working...

[@EI5EM]

Yes it works fine for me.

[@tixilx]

Great to see that you got around to making the band pass filter Tony - nice construction and fantastic to see just how well it worked. Were you using the Yagi ? 73 Gerry

[@EI5EM]

Later used Yagi but not for tests Gerry. Mni tnx

[@tixilx]

@@EI5EM Great stuff Tony - lovely audio off the wee Baofeng

[@nikola.makarska]

wery good fiter

[@MattL.-KE0SAW]

What determines the frequency range the most?

[@EI5EM]

The size of the cavity and precise adjustment of capacitor gap.

[@MattL.-KE0SAW]

@EI5EM I figured out that the gap made a difference, but I wasn't sure if the size of the container and the spacing of the items in It played that big of a roll. Thank you!

[@EI5EM]

The dimensions of the cavity, the inductance of the coils and the capacitance of the capacitors are all factors in bringing the unit to resonance at the desired frequency, Matt. It outperformed my expectations. It's not pretty, but it works ... de Tony, EI5EM

[@MattL.-KE0SAW]

@EI5EM I made one, and it was pretty rough looking, but it did the job fairly well. I appreciate the video and the knowledge that you and others have passed down to other hams. Thank you! 73 from Ke0saw

[@nosaj205]

Do you think it would handle 50 watt mobile?

[@EI5EM]

It should, it looks sturdy enough.

[@workofthedivinemercytv1302]

Good job host DV7BKG 73s

[@EI5EM]

Mni tnx

[@ranggakoencoeng209]

i from indo...you demontration is' good ok

[@franciscoalbuquerque6421]

Melhor filtro e radial liga gnd

[@simeonevincenzo]

Tony penso che tu sia Italiano, visto il cognome che hai. stammi bene 73

[@EI5EM]

My surname is Irish language

[@glenmartin2437]

Thank you. N0QFT

[@47dirtyden]

Well done that man ; Denis 2m0doi

[@EI5EM]

@@47dirtyden mni tnx

[@EI5EM]

@@47dirtyden many tnx denis

[@erwe1054]

[@simeonevincenzo]

good job end great product ,73 de iz8std