Відео

It covers most of the band, It is too wide for use as in band notch filters. Like operating CW and SSB on the same band. I don't have a vna or spectrum analyzer to measure one. But others online have done it, I may have a vna soon.

I understand, I used the video from Farhan, He makes it look simple but it took me 3 or 4 tries. I still think I'm a little off do to my low freq hearing.

Thanks, I know its an old vid, But I will soon have a mini VNA I want to learn. Then I can revisit this and actually measure the attenuation and width.

Yes, In this application. There are stubs used as matching sections for antenna tuning that are used in series.

I placed it just a couple feet from the rig with good results, I have not tried any other placements. It will help on other noise, if the noise originates out of band. Harmonic suppression is in the mid to high 20s DB depending on the coax used. The next step is band pass filters that have three times more attenuation. I use both. After this vid was made I got a 20m and 40m filters. These are much better and much more expensive. Using the stubs with the filters makes it even better.

I have had the same thought for a broadcastify receiver. I was going to use a uv5r but the front end is too weak and broad. My other vhf activity at home would overload the uv5r. I may give it a try. Sorry it took so long to reply, I have lots of video ideas but not a lot of time. I haven't been active in a long while

It's not when using one stub, I'm still looking into using two stubs. I have found mixed info on that. Two stubs work better than one but placement of the second stub can be optimized. I need to study that some more. Thank You for watching. 73

@@amrwhiskey3456 thank you very much for your reply. i will take more information. 73 many thanks

Thanks for the comment, I have been wanting to do a better video just on this topic, The AGC and using the RF gain control effectively. I have a lot of topics to cover but not a lot of time, Stick with me and I'll get some of it done. Thanks for the sub. 73

Since the impedance repeats every half wave ,you can measure the electrical length with an antenna analyzer. so you trim (tune) the length by the impedance or reactance measurements. here is a link to the article if your an ARRL member p1k.arrl.org/pubs_archive/105771

Sorry for the late reply. Yes 100 watts is what I have used. I have not tried more power

It might work but I don’t know how wide the notch would be. 433 and 439 are not harmonics of each other.. Most repeater builders would use a crystal filter for that. You would need to use a low loss coax at UHF. LMR 400 or 600. It would be a good experiment that would not cost much. a quarter wave at 433 is not much coax

@@amrwhiskey3456 could you add two stubs tuned either side of the desired frequency to filter it better? Perhaps also variable capacitors so the stubs are easily tunable?

@@izzzzzz6 the stubs are not sharp enough for that, they cover most of the band. But you can add more stubs for better attenuation.

well..years ago i read a Consumer Reports article about alkaline batteries .There was really no difference in performance. At that point in time they recommended buying the lowest cost brand. that was probably well before the Chinese brands .

amrwhiskey34 excuse me? did you say "Chinese brands"? that is a very ignorant statement; I suggest doing research of manufacturing plants and brand names. most products in some form are manufactured in Chinese manufacturing plants, this is nothing new and has nothing to do with quality. this would be too lengthy to describe so I suggest doing research on the matter. alkaline batteries just like anything else, quality differs by brand. you can buy the cheapest of the cheap but don't expect them to rival the most pricey brand, also there are varying factors of pricing. stores could make their own pricing and sometimes the manufacturer recommends a price and endorses that price. there's so many factors that come into play blaming the manufacturer is just very ignorant to do and also incorrect

@@mikelonas4508 *triggered*

Thanks

Thanks

It does. I want to finish this project with a new power supply for the router. I just haven't got to it yet. I have a few more Vid ideas. I'm just slow at putting it all together.

Thanks for the sub

That stinks, Did you get it cleaned out or have to replace it ?

amrwhiskey34 replaced

That is too bad.

+cpg0000 Thank you. I had planned follow up field day vid with multi transmitters on site. I will this year. I am also going to build some 80 meter stubs