HAM RADIO: Is it ALL about achieving a low SWR?

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Tim G5TM

Tim G5TM

Күн бұрын

Пікірлер: 106
@ZL1BQDRoly
@ZL1BQDRoly 4 жыл бұрын
Great video Tim. Perhaps a couple of additional caveats and maybe the subject of another video. 1. Shorter lengths of coax can become a problem at VHF/UHF and beyond IF they just happen to be an exact HALF wave multiple. Not such a problem at HF frequencies. All of our modern day solid state rigs want to look at a current fed load. In days gone by when most rigs were valve type rigs they in general wanted to look at a voltage fed load (hence the greater use of open wire feed systems in the past). 2. An inline tuner will ADD to your system losses, thus compounding the problems of using RG58 at higher frequencies. The tuner will keep the TRANSMITTER happy but otherwise fool the system (operator) into thinking all is well. ( I am a great fan or resonant antennas where a tuner is not necessary and so eliminating one source of potential losses) Cheers
@timg5tm941
@timg5tm941 4 жыл бұрын
Great points Roly. Really appreciate your input here 73
@paulkazjack
@paulkazjack 2 жыл бұрын
@David White why not?
@paulm0hpd319
@paulm0hpd319 2 жыл бұрын
Adding a tuner will allow the transmitter to put full power continuously into the system reducing losses, if there's a mismatch the transmitter reduces its power output to the difference of the mismatch, if there's a 10% mismatch then the transmitter is producing 10% less power ,add the tuner it produces 100 % full power
@MikeM0XMX
@MikeM0XMX 4 жыл бұрын
Another very good vid. Also a MASSIVE THANK YOU for the reommendation. Means a lot and very appreciated. 73 Mike M0XMX
@timg5tm941
@timg5tm941 4 жыл бұрын
You’re welcome Mike and thanks for stopping by 73
@M0SZT
@M0SZT 4 жыл бұрын
I really like your focus on M7's when out on the air, giving new operators the chance to get contacts especially DX is very important. Good point about calculating loss in your coax as well as your antenna esp VHF. 10 watts out of the radio and 4 watts into the antenna is not ideal
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Carl appreciate the feedback! 73
@BoB4jjjjs
@BoB4jjjjs 4 жыл бұрын
Quite right, every new operator requires a bit of encouragement to talk on the radio, please do not just give them a signal report and vanish, think how deflated you were when someone did that to you. If you find it hard, some do, ask them their QTH, when they passed, where they passed, if at a club ask which one. Of course there is the classic questions like the rig they are using, the aerial, the coax, and how high is it? Just keep them talking for a few minutes, it will build their confidence a bit. Give them advice and ask if there is any advice you can give them? All basic stuff, but they will appreciate it and you might earn a bit of respect from them. Don't worry if they ask a question you can't answer, that will only keep the conversation going a bit longer when you tell them who is the best person to ask. Then you can drop in going to the local club. Carl, it is not aimed at you. Just trying to encourage anyone who reads this to think and encourage new operators. As a seasoned operator, all of you have a lot to pass on to the new operator. Also it makes new friends, even though you may never meet them! :-)) Thank you for reading. Oh, some plugs for coax leave a lot to be desired as well, the ones with nylon centres can melt with high power, don't save a penny or two on those either.
@RianGalway193
@RianGalway193 4 жыл бұрын
bob fourjs You are spot on there dude, I often here full license holders just a quick contact with M7 newly licensed. When I was an M6 I was lucky that an older gent called Albert G3ZHE kinda took me under his wing he was my first QSO on 2m and he invited me to his house to see his shack, there on his bench was an Icom 7851 he let me operate on it and that was amazing. We have a good friendship now and it’s because he gave me good advice and actually chatted to me about common interests.. 73 Ryan 2E0IJJ
@boxingday11
@boxingday11 4 жыл бұрын
Nicely examined Tim, and well explained, thanks for the upload, regards,Carl.
@timg5tm941
@timg5tm941 4 жыл бұрын
Pleasure Carl 73
@ben2e0omr
@ben2e0omr 4 жыл бұрын
A well thought out and explained video Tim. Thoroughly enjoyed and reinforced my knowledge. Thank you for your continued input.
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Ben appreciate the feedback and glad you enjoyed. 73
@26CW128Jake
@26CW128Jake 4 жыл бұрын
Such a shame to see a dislike as soon as the video is uploaded, they haven't even had a chance to watch it! Worry not, Tim! I've liked the video for you!
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Jake appreciated! 73
@garryvandeensmith2133
@garryvandeensmith2133 4 жыл бұрын
@@timg5tm941 Have another like 👍
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Garry appreciated 100% 73
@williampd9wac947
@williampd9wac947 4 жыл бұрын
Jake, i was one of them..... Hahhaha.... no i wasnt... 👍
@MrScotchpie
@MrScotchpie 4 жыл бұрын
I learnt recently that every like and dislike is still considered by YT as interaction and helps promote the video. So even the dislikers are helping lol.
@michaelwylde1065
@michaelwylde1065 4 жыл бұрын
Really enjoyed your video Tim, great explanation of the standing wave ratio and also the coax loss. Great to put you in the log the other night also. Look forward to the next video already. 73, MM7MMW.
@timg5tm941
@timg5tm941 4 жыл бұрын
Recognised your call immediately Michael great you work you and many thanks for the kind comments. 73
@widdy4
@widdy4 4 жыл бұрын
Fab video! Really informative :-) RG58 is definitely a thing of the past now for me, especially seeing that huge loss in power! I am on hf more than any and use RG mini 8. However my 2m & 70cm does need maintenance so it’s gonna be hyperflex for me :-) Thanks again 2E0SQA - Cath
@timg5tm941
@timg5tm941 4 жыл бұрын
Glad you enjoyed it and good luck with the revised set up! 73
@BoB4jjjjs
@BoB4jjjjs 4 жыл бұрын
That is a good way of putting it across about coax losses. Spend what you can on coax for base stations, if you have anything left look for a very good antenna/aerial, if you have nothing left you are better making one out of wire than put up with cheap coax. Most Amateurs.Hams have done it (they will never admit it though) using RG58 and wondering why they are not getting out as well as they thought! Importance rating: 1 Coax, 2 Aerial/antenna, 3 Radio. Coax is going to serve you for years and so is the aerial/antenna and they may be high up and difficult to change. The rig and everything in the shack you can change a lot easier. Better to spend less on the radio and more on coax and the aerial/antenna, you can always upgrade the radio/transmitter. Anyone second that?I do forget to stop sometimes!
@timg5tm941
@timg5tm941 4 жыл бұрын
Great points Bob totally agree 73
@tristan4777
@tristan4777 4 жыл бұрын
Thanks for the video. So easy to spend a load of money on a station and then to be put off by poor performance. to then potentially sell up. Great timing with so many M7s, may be we can keep a few of them interested.
@timg5tm941
@timg5tm941 4 жыл бұрын
Let’s hope so Tristan and thank you for commenting 73
@TheTechPrepper
@TheTechPrepper 4 жыл бұрын
This is a great topic, Tim. As a new ham, I’ve been finding myself getting overly concerned with just the SWR reading on my analyzer and ignoring the feed line. I made precisely the mistake you were talking about when comparing RG-8X an LMR 400 in my system. I was able to tune both to ~1.3 SWR. Clearly, they are not apples to apples. I’m documenting my experiences on my channel, so I’ll be sure to mention where I learned this important lesson. Keep up the good work!
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks very much and I look forward to seeing the results! 73
@roger5809
@roger5809 4 жыл бұрын
Very well explained, thank you.
@timg5tm941
@timg5tm941 4 жыл бұрын
Thank you! 73
@BoB4jjjjs
@BoB4jjjjs 4 жыл бұрын
I found one I hadn't subscribed to off your list. Not much wonder I have problems catching up!
@TomG2NV
@TomG2NV 4 жыл бұрын
Superb Tim and possibly the least emphasized subject for those new to the hobby. All the attention is drawn toward the shiny kit so often when the fact is the business end of any station is the antenna & feeder! not glamorous but its what gets the results. I don't even use RG58 for patch leads, lol.
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Tom! It’s all about the feeder alright! 73
@migsvensurfing6310
@migsvensurfing6310 3 жыл бұрын
Thats why it is best to have the preamp and pa at the antenna instead of at the station. Thanks for the video.
@M0RMY
@M0RMY 4 жыл бұрын
Great explanation Tim ! Hence priorities: 1: Tuned Antenna 2. Low loss Coax (NOT RG58!!) 3. Radio.
@timg5tm941
@timg5tm941 4 жыл бұрын
Fully agree Tom! 73
@ae1tpa92gwtom2
@ae1tpa92gwtom2 4 жыл бұрын
Hi Tim, yes i was going to mention the silly thumbs dn as well,.. like yr vids Tim,.. coax is so important .. only hope remained was antenna gain,.. cheers , 73
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Tom I couldn’t agree more 73
@heribertosoto6567
@heribertosoto6567 Жыл бұрын
@10:10 You hit the nail on the head. Buy the best coax possible for the frequency of operation. DB loss of feed line is unavoidable but can be minimized. We all need to stop looking to tune an antenna with a swr meter. Understanding what impedance is and how it equates to an swr is the key to maximum transfer of power from the source to the load. Using a 1/2 wavelength increment of coax will replicate the load impedance to the source.
@OntheMicwithMike
@OntheMicwithMike 4 жыл бұрын
great informative info, and easily understood. Excellent stuff once again sir! 73' :)
@timg5tm941
@timg5tm941 4 жыл бұрын
Cheers mate! Hope all is well 73
@OntheMicwithMike
@OntheMicwithMike 4 жыл бұрын
@@timg5tm941 all is well on the eastside :) hope you're all staying safe and well over on the westside. 73'
@timg5tm941
@timg5tm941 4 жыл бұрын
Great to hear! On the west side... just about coping lol 73
@mikes6844
@mikes6844 4 жыл бұрын
Great advice, buying from unknown sources can increase losses even more. Quality coax, quality connections to go with it. 10 PL 259’s for £10 is a false economy, buy from a known source where you can be assured connectors have been manufactured to close tolerances. As you illustrate so well losses all add up. 👍🏻👍🏻👍🏻 73 de M0AZE Mike
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Mike. So many forget how important coax and connectors are! 73
@ianxfs
@ianxfs 4 жыл бұрын
Good one Tim. 18W 😮 Should come with a bedtime warning that video...
@timg5tm941
@timg5tm941 4 жыл бұрын
lol thanks Ian
@vimmeh
@vimmeh 4 жыл бұрын
Great Vid Tim :) Antennas and radios come and go, but the biggest purchase to make for a longer return on investment is the coax feeder. Buying the best coax you can afford along with decent connectors and external weatherproofing will pay dividends in the years to come - buy cheap buy twice, or miss out on those weak signals :)
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Colin, I totally agree 73
@markg6jvy135
@markg6jvy135 4 жыл бұрын
Great video Tim 👍 What’s your thoughts on connectors for 2/70 should we be moving away from pl259s?
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Mark. Well conventional wisdom recommends N connectors especially at UHF. However this article is also interesting: www.iz2uuf.net/wp/index.php/2016/01/08/pl-259-vs-n-on-430-mhz/
@markg6jvy135
@markg6jvy135 4 жыл бұрын
Yes I saw that and looked at the pictures of the connectors and dismissed it glibly as poor quality, but was glad to see he’d done a follow up article where he rules that out. Definitely food for thought and swimming against convention 👍 Cheers for the heads up.
@TEGEscalator
@TEGEscalator 4 жыл бұрын
best 73 Tim, nice reminder of coaxial attenuations. Always look at the specs before using a coaxial. To have the least possible losses.
@timg5tm941
@timg5tm941 4 жыл бұрын
Totally agree! 73
@M0RSF
@M0RSF 4 жыл бұрын
Very interesting video Tim as always. Being a QRP operator I use Ecoflex 10 with the compression connectors to feed my Diamond V2000. As you say decent coax is vital. Hope all is well. I have a video planned for this weekend that may be of interest to you and a couple more of my regulars. 73 Chris M0RSF
@timg5tm941
@timg5tm941 4 жыл бұрын
Look forward to that one Chris thanks for stopping by 73
@mattdixon5299
@mattdixon5299 4 жыл бұрын
Good video Tim, a good topic choice! I found it helpful. So thanks!
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Matt! 73
@sandraabarca6029
@sandraabarca6029 4 жыл бұрын
informative and timely..I use Messi aND Paloni coax excellent quality.73
@timg5tm941
@timg5tm941 4 жыл бұрын
It sure is excellent coax! 73
@mike-M0MSN
@mike-M0MSN 4 жыл бұрын
Good stuff mate..
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks mate 73
@Davidm-M0TPT
@Davidm-M0TPT 4 жыл бұрын
Nice one Tim I have been having similar conversations with some local operators :)
@timg5tm941
@timg5tm941 4 жыл бұрын
It’s often an over looked aspect! It does make me smile when I read on social media when an operator thinks their replacement lower loss coax is rubbish because their swr is higher than with their rg58 ! 73
@williampd9wac947
@williampd9wac947 4 жыл бұрын
Nice video Tim !
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks William! 73
@Cardassiaprime
@Cardassiaprime 4 жыл бұрын
Really good explanation of vswr-coax there Tim, I'm pretty Au fait with it all excepting the math you gave, but what i would say is if I was not a technically grounded person, what you gave folks in 15 minutes would have taken hours of google after google until it made sense. I can't believe I've only just found your channel (My Bad) after following the big licence debate on zoom hosted by Callum - the Notorious DX Commander. Your channel comes across as a Practical Everyman Ham Radio V-log (read- This is the straight dope) I'm Hooked! Saturday afternoon- in between re: feng shui my shack- I am Back to Back watching your vids and liking the QSO's with a summary at the end. 73's Keep up the great work. Barnie-M7PBX.
@timg5tm941
@timg5tm941 4 жыл бұрын
Barnie it’s great to have you on board and I’m glad you enjoy the videos. Really appreciate the support 👍👍 73
@Paddy_Roche
@Paddy_Roche 4 жыл бұрын
That’s a great video Tim, how it’s got dislikes is beyond me? Er actually probably jealousy. Are you a Teacher Tim? Certainly very professional delivery. 10/10 Tim keep up the great work you are doing for the New Folk coming into this awesome hobby.
@timg5tm941
@timg5tm941 4 жыл бұрын
Paddy that’s very kind of you. Yes I am a teacher at a college! Thanks for stopping by and commenting - greatly appreciated mate 73
@michaelm1keyhardy865
@michaelm1keyhardy865 4 жыл бұрын
Not into technical stuff but love knowing about things, Its a learning curve thank you. 73 Mike M1KEY
@timg5tm941
@timg5tm941 4 жыл бұрын
Every day is a school day in this hobby for all of us I think! 73
@dasy2k1
@dasy2k1 4 жыл бұрын
Do you have a link to a decent comparison chart for coax?
@BoB4jjjjs
@BoB4jjjjs 4 жыл бұрын
Look through DX Commanders videos.
@timg5tm941
@timg5tm941 4 жыл бұрын
Hi Daniel .. it won’t let me post a link here but simply google coax attenuation chart and lots will pop up to choose from, 73 and thanks for stopping by.
@BoB4jjjjs
@BoB4jjjjs 4 жыл бұрын
www.universal-radio.com/catalog/cable/coaxperf.html
@RianGalway193
@RianGalway193 4 жыл бұрын
Great video Tim, I’m currently studying for my full license after failing the old syllabus once. I am going to try to study as often as possible.. I’m not a technical kinda guy and music is my forte. I love amateur radio though. I enjoy your videos, Carl and Callum’s stuff, I don’t really watch any of the American ham channels. Thanks Tim. Ryan 2E0IJJ or when I’m a rebel 26 CI 081 😂
@timg5tm941
@timg5tm941 4 жыл бұрын
Good luck with the studying Ryan! Very glad you like the content and thank you for stopping by 73
@cwoodalluk
@cwoodalluk 4 жыл бұрын
I got one of those Italian meters and the SWR is whatever I like as I turn the button to select it. Am I missing something?
@timg5tm941
@timg5tm941 4 жыл бұрын
Which meter Carl?
@cwoodalluk
@cwoodalluk 4 жыл бұрын
@@timg5tm941 Zetagi 102
@MikeM0XMX
@MikeM0XMX 4 жыл бұрын
@@cwoodalluk Carl, check this out, it may help. kzbin.info/www/bejne/pmXUk2aArMlogck
@TomG2NV
@TomG2NV 4 жыл бұрын
@@cwoodalluk I suspect you might be missing something Carl, you might want to watch this kzbin.info/www/bejne/p4TIkmh8n8iHeqc video to understand what's involved in adjusting the calibration =CAL control to obtain an acurate reading from that type of meter.
@paulm0hpd319
@paulm0hpd319 2 жыл бұрын
Is all the 11% reflected power deemed as lost ? It undergoes feedline attenuation back to antenna with the remainder joining the forward power back to antenna
@AliK-ql5lv
@AliK-ql5lv 4 жыл бұрын
Thank you Tim, I really do despair when I see or read people using or recommending RG58. Even the RSGB recommend at least RG213 for HF. RG58 is totally obsolete, has been for ages. It was invented during World War two and named "Radio Guide" 58 as it was the 58th cable to be listed/invented/named by the US wartime agency the "Army-Navy R.F. Cable Coordinating Committee", set up in the early 1940's. Materials science has come a long way since then. Much better coax cable is available at similar cost these days. Also, there is a lot of substandard 'fake' RG58 available online, so as always, buyer beware. Why on earth people spend good money on Transceivers and antennas then connect them with the cheepest rubbish they can buy, it just begars belief. There's only one place RG58 belongs and that's in the bin !
@timg5tm941
@timg5tm941 4 жыл бұрын
Completely agree 73
@BritishBeachcomber
@BritishBeachcomber 2 жыл бұрын
I'd be interested to hear your thoughts on balanced ladder feeder, 450 ohm with 9:1 balun in the shack. Seems a bit out of fashion, but far less lossy.
@timg5tm941
@timg5tm941 2 жыл бұрын
I’m a big fan of doublets using 450 ohm. But I’d never feed one with a 9:1 as the impedance for each band will be all over the place. I’d use a 1:1 or at a push a 4:1. 73
@AndyWragg
@AndyWragg 4 жыл бұрын
It's a shame that this subject is only taught in detail at the Full license level. Using good quality coax makes such a difference. I had to retune my contest antennas after I changed from using Mini-8 to Ultraflex 10, and my scores improved as a result.
@timg5tm941
@timg5tm941 4 жыл бұрын
Hi Andy yes mate it’s a no brainer for sure! 73
@ndrthrdr1
@ndrthrdr1 2 жыл бұрын
Can the swr be measured on an HT? I wonder about the effect of a Signal Stick or other upgrades to the rubber duck. I’m about to receive an ICOM ID-52, and I’m worried about changing anything from stock.
@timg5tm941
@timg5tm941 2 жыл бұрын
HT's tend to be more forgiving to high swr. Yoiu should be ok with that antenna.
@martinvanek5951
@martinvanek5951 4 жыл бұрын
Makes me think I should put a watt meter at the antenna to see what power actually gets to it. I use LMR 400 for my VHF antenna.
@timg5tm941
@timg5tm941 4 жыл бұрын
Be interesting to see! 73
@NoMoreRadioMyths
@NoMoreRadioMyths 9 ай бұрын
Not right. "with moderate lengths of low-loss coax, such as we commonly use for feed lines, loss of power because of reflected power in the hf bands can be insignificant, no matter how high the SWR. For example, if the line SWR is 3, 4, or even 5 to 1 and the attenuation is low enough to ignore the reflected power, reducing the SWR will yield no significant improvement in radiated power because all the power being fed into the line is already being absorbed in the load." That from antenna engineer Walter Maxwell who wrote extensively on the misunderstanding of reflected power losses. If you transmit 50 watts to the antenna and 25 watts is reflected back, that in turn is reflected back to the antenna. So now you have 75 watts (50 watts + 25 watts) headed to the antenna, and the antenna radiates full power of 50 watts. The only important thing is use an antenna tuner so the transmitter sees about 50 ohms or an SWR of now more than about 1.5 to 1.
@nethoncho
@nethoncho 4 жыл бұрын
2E0EZT Sent me here
@timg5tm941
@timg5tm941 4 жыл бұрын
Thanks Ben it’s good to have you onboard 73
@rttakezo2000
@rttakezo2000 4 жыл бұрын
I appreciate what you're trying to do in this video (I enjoyed it; as a US General). However, given at the beginning you implied this was for new hams, I think you flew over their heads with the discussion of inter-relationship between cable loss & SWR but not showing the math. Some diagrams/pictures & shown calculations would likely have made it easier to follow.
@timg5tm941
@timg5tm941 4 жыл бұрын
Hi and thanks for commenting. I decided not to show the math as I thought it would make the film too detailed and cause it to become non user friendly to new operators. Some people switch off when they see numbers ( being a college lecturer teaching adults myself I know this). So the intention is to gently introduce the impact of feed line loss to new operators and to give them an overview of its impact. Appreciate you stopping by and 73.
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