One of the most important station accessories: band pass filters
ฝัง
- เผยแพร่เมื่อ 14 ก.พ. 2023
- Do you want to do a group activation or field day operation without stepping on or covering each other up? Band Pass Filters to the rescue!
Morgan Systems Band Pass Filters:
www.surgestop.com
Like what you see? You can leave me a tip:
www.paypal.me/kb9vbr
KB9VBR VHF/UHF Antennas:
www.jpole-antenna.com
Become a patron! Unlock exclusive content at: / kb9vbrantennas
Support Ham Radio Q&A by shopping at Amazon: amzn.to/2kO6LH7
My Parks on the Air setup:
Transceiver: amzn.to/3lmHoei
Battery: amzn.to/3xBGgbv
Tuner: amzn.to/2ZCNM9l
Folding Table: amzn.to/3xFIp5Z
Throw Weight: amzn.to/32QW2nB
Video Production Equipment:
Camera amzn.to/32UaXNX
Lens amzn.to/31mmDrX
Wireless Microphone: amzn.to/3xFVBb4
Microphone: amzn.to/3daoAdq
GoPro: amzn.to/3pkmP30
Music by license:
www.premiumbeats.com
www.soundstripe.com
As an Amazon Associate, I earn from qualifying purchases
Contact Information:
Questions, comments, or business inquiries may be directed to kb9vbr@jpole-antenna.com. If you wish for your product to be featured on my channel, please contact me.
#Hamradio #AmateurRadio #POTA #ParksOnTheAir #portablehamradio #bandpassfilter #filter #bandpass - วิทยาศาสตร์และเทคโนโลยี
Thank you, Michael. Another video with content immediately relevant to my Ham Radio current & future needs. All the best, fm KQ4IXD
At four minutes, I had to put on my glasses - I saw smoke and I thought that your rig was on fire. LOL!
Just letting the smoke out...
I spoke with them (Morgan) today. They asked me where I heard about them (seems they have had an uptick in orders) I told them about the video and sent them a link.
Elsie™ is a remarkable piece of software that I’ve used in the design and construction of several 7 pole band pass filters. K4VX also offers several functional designs in his paper, Band-Pass Filters for HF Transceivers. Great topic, Michael. 73 de KO4CES
I've seen some plans online and I've got building one my project list.
I managed to score two full sets from a guy right before winter field day this last January. We operated in 3O category and had two CW stations running simultaneously with a phone station for at least half the contest. The CW stations were absolutely killing the phone station. Installed the band pass filters, bing bang boom, no problems. Great video!
When 2 rigs are operating in close proximity (i.e. field day, etc...) the most critical bandpass filter is the one on the lower frequency transmitter. Those harmonics are front-end killers, and the higher frequency radio's bandpass filter is no help with that. 🙂
KZ9V
I agree. In the scenario where operator A is running FT8 on 40M, and operator B is running phone on 20M or 10M, the harmonics from the 40M can fall into operator B's band. A bandpass filter on transceiver B will not block these frequencies - doing so would block the very band it is trying to use. Placing a bandpass or lowpass filter on the 40M rig should attenuate the generated harmonics sufficiently such that the FT8 transmissions do not impact the phone operation. Just remember that the power handling capability of the filter needs to equal or exceed your rig's Tx power. In the case of the Morgan 100W filters, I probably would not operate a digital mode such as FT8 at much more than 25 watts.
Excellent description and demonstration Michael, pro tip as always Sir.
We made band pass filters for 80, 40, 20, 15, 10m for WFD this year. Ours would only work with both stations using them, which did not happen. Three 7300 users within 100 yards and my IC-706 was a recipe for disaster. I had coax issue for the first two hours so I didn’t notice the issue until later. We had fun and made contacts, that was the point! The interference was annoying, so maybe Summer Field Day we will get more use from the filter set. By the way, they are the built from the Sept 1988 QST article by Lee Gordon, K4VX. Tuning almost requires a NanoVNA. Thanks for the video Mike!
Building a band pass filter isn't a monumental task, but you do need a few specialty tools, like a vector meter and a method to properly measure the values of your inductors.
@@KB9VBRAntennas Mike you are spot on!
Excellent video as usual, Michael. Been using band pass filters for all our multi-op events. We found the filter helps the users of the frequency (obvious) but also the other users not on that band.
Great video. I might add that using tuned antennas is a must when using band pass filters as most them want to see a low swr to work properly. Using a 9:1 antenna with a tuner isn't a good idea.
Great video! Thanks for explaining these filters.
Great video as usual Michael.
Great info Michael! 73!
there are also band stop or notch filters. My personal favorite. I'm willing to bet the high reflection (SWR) caused by transmitting out-of-band on a filter will make some transceivers unhappy, potentially overheating the power FETs on the PA.
Thanks for this video Michael! I was just talking about this at our past winter field day.
Good video. Thanks!
Great video, thanks for clearing that up for those of us still learning!!
Michael, As always, great information and easy to understand, Keep up the great videos!
An impressive video that let me learn something, thank you.
Great video and topic
Thank you for this video. I have been looking into band pass filters since Winter Field Day. I was planning on building some, and likely will build one for the learning value. Very good to find a quality source already built. 73 de KD9NNZ.
Building a filter isn't a difficult task, there are formulas and plans online to guide you. You will need some tools like a vector analyzer and meter capable of measuring inductance, though. If you build one, let me know how it turns out.
Great video! Thank you!
Thank you for sharing this good information 🙂
More videos like this one, please. U-rah-rah
As always a very interesting and useful video
Thanks for sharing / 73
Great video! Thanks. At 3:55 I got worried about your radio because it looked like smoke was coming out the back! : ) 73
Any chance you could compare the Morgan Systems "Legacy" models with their new "High Performance" versions? How about a comparison between the Morgan Systems filters and the ones Array Solutions sells?
Great video Michael! Why is the metal enclosure so large if the components inside are so much smaller? Heat dissipation?
Air wound inductors can be quite sensitive to other things in proximity of them. A bit of spacing keeps them from interacting with each other.
Thanks for the easy to understand explanation.
Michael, we just bought a set for our Club-all Morgans and the highe performance models for improved filtering. Do you use the ground terminal at all in your installation? Why ir why not?
WOW they price has gone up! They are not 140$ each. I ordered 2 of these. My Friend and I have started doing POTA and are going to do a field day this year. He operates Phone on 20 and I run FT-8 on 40 meters. When he operates he is just killing me to the point that I can only use FT-8 because of the interference. I run a IC-7300 and a IC-705 the rig he runs is IC-706. I hope these help us out, if so they will be worth it. Thank you for all your helpful videos.
Morgan Systems sells two versions of its filters. The legacy filter is a 3-pole design, which is adequate for most circumstances; and that is $80. They also have a high performance version which is a 5-pole design and offers a higher level of attenuation. That one sells for $140.
@@KB9VBRAntennas I did not know that but I think I would have went with the better one anyway. We really want to do the POTA together and last time we just took turns 30 min each but it was boring. If they work they will be worth it to me. The 705 was not cheap either but should last me the rest of my life! Thank you again for the video, I was getting desperate and was thinking of buying some of the junk off ebay but they had bad reviews and they were 100$ each. I hopefully if they work good I will pick up one for 15 and 18 meters I like those bands as well. I always seem to end up on 15 meters, I started there 44 years ago when I got my Novice. A friend had a old broken vertical he gave me, It only worked on 15 meters but it sure worked good there.
These filters are worth the money. Dave, KZ9V, and I operated multi-multi mobile for the Wisconsin QSO party, me on phone and him on CW. Both antennas were on his truck and the filters worked flawlessly. I've also used them for multi-activator POTAs and Field Day with great success.
@@KB9VBRAntennas Thanks for the info. If it worked for you guys both on a truck it should work for Glen (KD8KMY and myself K8OCN) in a field. We are going to do field day in my back field this year (have not done a field day in 20 years) and we were thinking of me going in the front yard and him in the back field but we would be s far apart we would not even be able to see each other and I am not thrilled about setting up in the front yard. If its a nice day and I get tired I will want to go sleep and leave it set up to come back to in the morning. Much safer in the back where no one can see it. Glen stays on 20 meters and I like to hop around always looking for better signals. I can see I will be buying more of them for the other bands if they work as well as I hope they do. 73
@Michael, where can one find bandpass filters for purchase these days? Nobody that I've asked seems to know, and the bandpass filters my club uses are quite dated and were purchased from a source that is now defunct. Thanks!
read video information ... Michael put the link 😉
The link to Morgan Systems is in the video description. www.surgestop.com
@@KB9VBRAntennas Thanks!
How is a band filter different then a choke? Another TH-camr I watch has what looks like a small piece of coax with 4 or 5 ferrite beads shrink tubed to it and places it at the end of this feedline just before the radio. He calls this a choke. Great video Michael, 73!
Chokes perform a different task than a filter. A choke, like you described, will reduce or eliminate any common mode current running back down the outside braid of the feed line. By blocking the return RF energy, they help prevent your feed line from becoming part of your radiating antenna.
@@KB9VBRAntennas Thanks for the clarification, Michael. Your explanation really helped frame the subject so I can dig deeper on the web. Cheers!
Thanks for a great video. It does look like the filters are up to $140 now at least for 40 meters which is getting pricey to buy enough for even three or four bands.
The legacy filters are still $80. They also make a high performance 5-pole filter that has more attenuation for $140.
Thanks Michael
@@ourrvtravels7183 Just Build one
Michael, thanks as always. I may not have been listening attentively enough, but what about the instance where a local AM station is slamming your rig's front end. [I hear online that evidently the Xiegu 6100 has this issue]. Which product would best take care of that?? Thanks! 73, Tim
The "high-pass" filter that Michael mentioned, or perhaps a "notch-filter," would be the best way to attack that problem.
KZ9V
A high pass filter will reduce the AM broadcast band noise. Morgan Systems also makes one designed for cutting broadcast interference.
3:55 Seems like the FT8 is too much for the radio ;)
Hi Michael! How are you liking those Morgan Systems bandpass filters? I've been thinking about picking up a couple of those for Field Day! Just wanted to know if you've got any thoughts on them.
They are working great. Dave, KZ9V, and I used the filters in our recent multi-multi mobile operation for the Wisconsin QSO party. The filters allowed us to operate without interference even though our antennas were very close to each other: th-cam.com/video/GZXWTGmlQ0o/w-d-xo.html
@@KB9VBRAntennas Sounds good! Thanks, Michael! Have a good weekend!
Hello,
Where can I find filters for Microwave frequencies?
Thanks!
That's a good question, maybe Down East Microwave would have a source for them.
Hey I could really use your help on something, whenever I read about 1:1 baluns or "ugly balun" (for the purpose of reducing rf in shack it says that you should wind up the coils close to the feed point of an antenna, I recently came across a video where the opposite was advised that if you don't want to feed RF Into your rig wind up the coils as close as you can to your rig. Please help me understand how it's properly done. If I had to guess at the rig sounds good because any line you leave out of the balun has a chance of radiating or creating unwanted skin effect so eliminating it closest to radio makes sense. But if so, why do all these other sources say at antenna feed point?
Thank you!
A choke or balun at the rig vs the antenna are serving two different purposes. We put chokes on the feedline for antennas that tend to generate common mode energy at the feed point, like end-fed antennas, or verticals with a poor ground network. This keeps the common mode currents off the feed line and the feed line from radiating. (Not that this radiation is necessarily a bad thing, but it can affect your overall RF radiation pattern).
Putting a choke near the transceiver performs a different purpose, and that's to help prevent the common mode currents from interfering with the transceiver's receiver. The devices are often also called line isolators. If you live in a noisy area (like an urban environment), a line isolator may help reduce that noise floor as the common mode energy isn't getting into the transceiver.
So the question is, which is better and do you need both? It really depends. If you are using an end fed antenna, adding a choke, along with a counter-poise, will help increase the effectiveness of your antenna. Does your station have a higher than average noise floor or you live in a residential area and have already explored removing local noise sources? Adding a line isolator as close to the transceiver as possible could help remove that noise a bit.
@KB9VBR Antennas can you put a choke at both the transceiver and feedline? I'm assuming because it calls for more cable it will result in some loss but is it worth coiling up on both ends. I do live in an urban area with lots of electrical noise, but my initial concern was because I just made a random wire 9:1 balun to reduce how much common mode currents are created during transmit but also to not have RF go back to transmitter and find my CW key, computer or worse my lip from the mic lol
Michael, a question: would you use / recommend use of a band pass filter - for just participating in POTA (not near any other radios/antennas)m or just calling CQ - especially CQ DX? My question revolves around QRM/QRN - and, it if seems uninformed, it is because I am learning. Thank you. KQ4IXD
I'd only use the filters if another station is operating close by. Their purpose is to filter noise outside your passband. Band pass filters can help to reduce overall noise, but their effect will be marginal because they won't be able to filter out the broadband noise that falls within their frequency window. But they can be helpful for noise outside the band.
Hi Michael,
Newby question:
For a QTH base station with long EFHW wire antena for multiband use, would adding a band pass filter at specific bands clean up the signal? If so, could one set up an array of 3 - 4 band pass filters on a switch to the same antenna to improve Rx/Tx on multiple bands?
No nearby source of high energy RF; this is a hypothetical question. I looked at the recommended website and they offer two levels of filter - older models at ~$55.00 and newer ones at ~$120.00. Maybe not THAT expensive, but if this is a dumb idea I don't want to waste my time and money experimenting on it. OTOH if there is potential merit I'll add it to the project list.
Thanks for great presentation as always.
73,
John KK7JBZ
Unfortunately, no. Unless your receiver is being decensed by a strong nearby RF source, your local in-band noise issues won't be solved with a band-pass filter.
KZ9V
@@davewhite7679 Thank you!
Dave's right. In the situation you described, band pass filters won't help. A common mode choke may reduce the broadband noise, though. Palomar Engineers make a variety of common mode noise filters to do that purpose. But often times looking for the actual source and eliminating it is your best method for cleaning up a received signal.
the good old days of wiping out tv and police
Just what I needed to know for our club POTA thank you KE8MWQ 73
73 DE #VA6LAT