Unveiling the Truth: Measuring Coax Cable Loss for Ham Radio Beginners

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  • Опубликовано: 3 янв 2025

Комментарии • 120

  • @BrokenCircuitRanch
    @BrokenCircuitRanch Год назад +12

    Everyone is always worried about how much of their output power is reaching the antenna and that is not what people should worry about. Its the tiny power that your antenna is sending back to your rig. Every db counts on weak signals and the difference between making a contact or not in many cases. You can always increase the transmitter power via amps to make up for any coax loss, but the other station may not.
    As a general rule, put in the best coax cable you can afford. Its the most important part of your station setup.

  • @mewrongwayKOCXF
    @mewrongwayKOCXF 9 месяцев назад +1

    Finally someone showing people how to test there coax rather than just pushing M&P claiming its the best!! Your the best Ape!! 👍👍👍

    • @TheSmokinApe
      @TheSmokinApe  9 месяцев назад +1

      lol, thank you and glad you liked the video 👍

  • @tmiller9099
    @tmiller9099 Год назад +5

    Excellent. Really makes you think twice about what coax to use in a vehicle for 2m and 70cm. Length is going to be short but the losses can be pretty high. Thanks!

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      Yeah, for sure. Thanks for watching 👍

  • @Swamp-Fox
    @Swamp-Fox Год назад +1

    Thanks for the S21 tutorial with the NanaVNA! Good sutff! Merry Christmas Ape!

  • @KK6USYHamRadioAdventures
    @KK6USYHamRadioAdventures Год назад

    Nice work Ape, pretty interesting.

  • @snatr
    @snatr 3 месяца назад

    Something occurred to me when you mentioned coiled cable @1:58. Considering we're talking about cable loss and not faults, I was thinking it might be a good idea to measure samples of the cable instead to determine which cable you might want to consider. Then do the math for the length you'll need. That's for someone in my case that has several types of old unmarked cable anyway 😏 Not sure it works that way, but thought I'd mention it.

    • @TheSmokinApe
      @TheSmokinApe  3 месяца назад +1

      You could do that and use like 1m lengths for comparison 👍

  • @hound696
    @hound696 Год назад +3

    Iv'e just upgraded from rg58 tp M&P HyperFlex 13 coax. Its very expensive but i wont need to upgrade for a long time, and the fittings are built like tanks.

    • @TheSmokinApe
      @TheSmokinApe  Год назад +2

      I’m running some M&P and you are correct, the connections are beefy 👍

  • @45auto
    @45auto Год назад +1

    Good stuff. I appreciate you sharing the various tests you can run on your equipment with both the NanoVNA and the TinySA.

  • @LifeAtTerminalVelocity
    @LifeAtTerminalVelocity Год назад

    Your videos are always excellent Ape.

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      Here I was thinking you only watched because I am cute

    • @LifeAtTerminalVelocity
      @LifeAtTerminalVelocity Год назад

      @@TheSmokinApe 🤣🤣🤣 well you found me out.

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      @@LifeAtTerminalVelocity I knew it! By the way, glad you like the videos bro 🍻

  • @bob_mosavo
    @bob_mosavo Год назад

    Thanks, Ape 👍

  • @RESlusher
    @RESlusher Год назад

    Thanks for the info, Ape! Merry Christmas to you and yours!

  • @godarklight
    @godarklight Год назад +4

    Coiling up the cable will only give you common mode inductance. Differential mode (what we use to get our wigglies to the antenna) is not affected by the coiling of the cable. Rest of the video is great, and this test is why I do the "through" calibration.

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Fair point about CMC, thanks for the comment!

    • @feeatlastfeeatlast5283
      @feeatlastfeeatlast5283 Год назад +1

      @@TheSmokinApe So, keeping that incorrect claim in the video perpetuates a myth. We have enough myths that hams believe.

  • @MrMudsHamRadioTime
    @MrMudsHamRadioTime Год назад

    Great video Ape. I also use nano vna saver as the device screen tends to become unresponsive when using it outside in the cold.

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      I use it mostly because of my bad eyes, lol. Thanks for watching Mr Mud 👍

  • @bobkopf227
    @bobkopf227 Год назад

    As I’ve said in the past I always learn something from your videos, thanks for the demonstration and for sharing

  • @FEPLabsRadio
    @FEPLabsRadio Год назад +1

    Good job professor!

  • @bassangler73
    @bassangler73 Год назад

    Good vid Ape! I'm a General Class ticket but I'm big into Storm Spotting and chasing so I can justify LMR-400..But for HF I have no trouble running RG-8X...Merry Christmas bro!

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Merry Christmas BA. Don't tell anyone but my main HF coax run is 8X 👍

  • @paulgarcia1566
    @paulgarcia1566 Год назад

    Thanks for the breakdown Ape.

  • @stevehildreth1934
    @stevehildreth1934 4 месяца назад

    I passed my Technician's license exam 2 years ago and I recently achieved my Amateur Extra, though I'm not getting much radio time. I am still exploring antennas and coax. I recently purchased the Nanovna H4, the one you are using in this video. I have not yet downloaded the Nanovna Saver software, that is another issue having just replaced an old balky Win 7 laptop. After all that, my question for this video is about the VNA calibration and configuration for coax testing.

    • @TheSmokinApe
      @TheSmokinApe  4 месяца назад

      Hey Steve. Here is a playlist where I cover tons of stuff with the NanoVNA including calibration and testing coax 👍

  • @ornithopterindia
    @ornithopterindia Год назад

    👍Thank you sir.

  • @Thump2030
    @Thump2030 Год назад

    Good Video

  • @vasilatosianis4208
    @vasilatosianis4208 Год назад

    Thank you for explanations realy great !

  • @truckinguy92
    @truckinguy92 Год назад

    I use RG-316 for my POTA activations. 25’ of ABR with the choke beads on one end which for my vertical I put at the antenna end and EFHW at the radio end since I use the shield as a counterpoise. If I need a longer run I use a 50’ piece of RG-316. The losses are fairly negligible at HF frequencies. Because of that I gladly take the losses over the advantage of the small coax package. I’ve taken a variety of different coax types and lengths and haven’t really noticed any differences. Thanks for the video.

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      Hey Trucking, I am the same way... I'll take the loss hit just for the easy cable 👍

  • @laszlokovacs8827
    @laszlokovacs8827 Год назад

    Another good video. I picked up some rg-213 for pota but just been too busy to try it. So what cable(s) are you running at your base?

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      I have a few feeds, mostly RG8x and some flavor of M&P.

  • @KS0JD
    @KS0JD Год назад

    Great video Ape. Some hams don't even think about cable loss vrs frequency. You have to look at the system as a whole. 73

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Hey Jeff. You are right, between tuners, coax and transformers the losses can add up quick 👍

  • @AA7WI-Mike
    @AA7WI-Mike Год назад +1

    Will the loss at 440 with only 7 feet of that cable be as significant ? My K-400 lip mount came with that cable for use with a dual band antenna. Great Video !!!

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      I wouldn’t worry about 7’ this cable was about 35’ 👍

    • @BrianFields
      @BrianFields Год назад +1

      At 7 feet, it would be around 1.45 dB loss for 70CM, and 0.73 dB for 2M.

  • @blugoose86
    @blugoose86 Год назад

    Great Video Ape. Even if you subtract the losses (which add up) of the connectors, it's obvious that you should select a different coax, or obvious how to choose the right coax for your application.

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Thanks James. When you combine losses from bother components like transformers and tuners you see it adds up quick 👍

  • @MikeN2MAK
    @MikeN2MAK Год назад +1

    Very cool. I knew this could be done with the NanoVNA but wasn't sure how. I'm curious what the loss differences are between a longer and short run of cable. I started using RG316 this year for POTA with the CaHR Mercury linked dipole and the N9SAB OCFD, since it puts much less strain on the mast for these antennas. I've got one cable that is around 20-25 feet and another that is around 30-33 feet, which was so I could put the antenna up higher. I'll have to check out what the difference is sometime. Thanks!

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Hey Mike. You’re correct the longer the cable the more attenuation. I’m willing to loss some watts to have the smaller cable 👍

    • @BrianFields
      @BrianFields Год назад +1

      Most coax loss specs are calculated @ 100ft (but check carefully, some are at other lengths, including meters). A 25ft. cable would be 1/4 of that, 33ft. would be 1/3. A good reason to keep your cables as short as practical.

  • @HamRadioWithKE0MAD
    @HamRadioWithKE0MAD Год назад

    Great video Ape. Its definitely eye opening when you just think -1db from a 100 watt transceiver is going to be 80 watts out, and 1db isn't bad.

  • @ohaya1
    @ohaya1 Год назад +3

    Thoroughly enjoyed that, Ape. You made a point about the coil of coax having impedance. Based on what I know, this is not a problem at all for this test since the impedance is against currents travelling on the outside of the braid only (choke) and won't impede RF travelling on the surface of the inner conductor. The coil should not affect the measurement at all. Do you agree? Alex, 2E0LUP

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      You are correct Alex, I would agree. Thanks for watching and for the comment 👍

    • @feeatlastfeeatlast5283
      @feeatlastfeeatlast5283 Год назад

      @@TheSmokinApe Ok, there you have two viewers who noticed the mis-statement. Let's get that corrected. What say?

  • @beaseac
    @beaseac Год назад

    Can you do a video on gow to measure the length of a cable... Or where a break is?

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      I can put it on the list. The problem is that you either need to know the velocity factor which seems like a hassle.

  • @markharrison1160
    @markharrison1160 Год назад

    I get the video was how to use the H4 ( you didn't show any menu settings ). The manufacturer spec sheet will tell you where that coax runs best as well.

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Yes, you can use the manufacture spec if you have it and you didn't get gas station coax. Thanks for the comment Mark.

  • @HOAHamRadio
    @HOAHamRadio Год назад

    Add another Chapter to TheSmokinApe Book of Ham Learning. Thanks

  • @acestudioscouk-Ace-G0ACE
    @acestudioscouk-Ace-G0ACE Год назад

    Thanks for another informative video Ape. I need to check your list to see if you have covered the subject of using coax lengths of half a wave length of the frequency band you are going to use. I've heard for and against on the merits of this... would welcome your opinion. 🤔 73 G0ACE

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Hey Ace, glad you liked the video. So using a havewave or multiple there of if the frequency is a best pratice but its not something I have done a video on. I could add it to the list but be warrned, it's a long ass list.

    • @acestudioscouk-Ace-G0ACE
      @acestudioscouk-Ace-G0ACE Год назад

      @@TheSmokinApeThanks Ape, I realise it's a contentious subject too!

  • @dougdaniels
    @dougdaniels Год назад +1

    Not just for beginners, a good reminder for everyone. 👍

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Fair point Doug, thanks for watching 👍

  • @mjktrash
    @mjktrash 4 месяца назад

    Did I miss the guidance on how to set up the test rig?

    • @TheSmokinApe
      @TheSmokinApe  4 месяца назад

      @@mjktrash pretty sure I showed it

    • @mjktrash
      @mjktrash 4 месяца назад

      @TheSmokinApe I saw the physical setup, was there VNA settings etc?

    • @TheSmokinApe
      @TheSmokinApe  4 месяца назад

      @@mjktrash standard SOLT configuration and the S21 Logmag measurement.

  • @SCTaylorTX
    @SCTaylorTX Год назад

    Can you use the same test to test through a BalUn/UnUn?

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      You can do the same measurement for a balun / choke. Here’s a video where I show how to measure the UnUn Random Wire Antenna FT140-43 Toroids Tested
      ruclips.net/video/6j1Yc1Y4Ly0/видео.html

    • @SCTaylorTX
      @SCTaylorTX Год назад

      @@TheSmokinApe awesome, thanks!

  • @DonzLockz
    @DonzLockz Год назад +4

    I need to buy a device that measures my exponential cash loss with this hobby!😕
    Thnx Mr Ape.😊

  • @imahamjim
    @imahamjim Год назад

    How long is the cable

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      I believe it’s 35’ but I could be mistaken

  • @ac4nl
    @ac4nl Год назад

    Yep.. Greetings...
    Nano-H4 is very nice for less than 100 dollars.
    Possilbe to mention Reflection losses due to coax as well !

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Hey BLE, you are correct these VNAs can give you visibility into what’s actually going on in your circuit 👍

  • @miker8379
    @miker8379 Год назад

    It’s very eye opening to put a wattmeter and dummy load at the end of the coax. I do however think the hype is overrated unless possibly you have to run the pre amp all the time.

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Yes, the wattmeter and DL is a good test for sure 👍

  • @brucekempf4648
    @brucekempf4648 Месяц назад

    How many feet of RG-316 were you using? I would like to know what the loss would be at 28 MHz for 20 feet of this.

  • @ynot6473
    @ynot6473 Год назад

    loss figures are available for most coax cables (db per 100 feet), useful for those who don't have a nano vna. either way one can soon work out which cable to use for the length and frequency to be used. 70cm in a car, RG58 is ok it only needs 10-15 feet. 10M with the antenna down at the end of your paddock, RG213 at least.

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      Hey not, I would agree with most of that. That said many folks reach out to me for help with their stations and don’t know what type of coax they have or they have a generic rg-58 or rg-8x and do not have a manufacturer data sheet. Thanks for the comment 👍

  • @MrSabram07
    @MrSabram07 6 месяцев назад

    I'm using 50 ft of rg8x on gmrs and the SWR increases when I step up the power on my radio. Is that normal? I know it sounds silly but I go down to two watts. I got 1.01 I go up to 25 while that's all I'm looking at. 1.7

    • @TheSmokinApe
      @TheSmokinApe  6 месяцев назад

      As crazy as that sounds, it happens.

  • @tomstrum6259
    @tomstrum6259 9 месяцев назад

    Including Rg-6 75 ohm Foam double shield would've been interesting as it's relatively Cheaper & has Less less loss than Rg-8....The 75 ohm coax has surprisingly less significant Mismatch loss & Vswr issues than you'd think for the cost...

    • @TheSmokinApe
      @TheSmokinApe  8 месяцев назад

      I know a few folks who use it, I haven’t yet 👍

  • @baykayaker7409
    @baykayaker7409 Год назад

    unable to read nano saver screen, very blurry. :(

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Sorry man, I will try to have it bigger next time!

  • @LeeMcc_KI5YPR
    @LeeMcc_KI5YPR Год назад

    👍

  • @shanerorko8076
    @shanerorko8076 Год назад

    The major issue all hams have is they think about coax in loss only.
    No one looks at the noise incurred by cable leakage.
    Say you have 100ft and you want to DX on 7mhz 40m, well RG58 will be something like 20% or 30% loss at like 1.5 to 2:1swr fairly standard stuff, the LMR400 might be something like 10% or better.
    This looks to most hams that there's no point in using LMR400 as it's like a quater of an S point difference.
    But what nobody realises is that there's probably going to be an S point in noise floor increase using the RG58, thus making the SNR way worse using the cheaper cable.
    Of course putting the coax underground helps and if you're in a quite rural area it might not make that much difference, but if you're in the city and it's noisy and you can't put the cable in a trench so it's above ground get the best cable you can.

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Thanks for the info Shane, it’s helpful 👍

    • @shanerorko8076
      @shanerorko8076 Год назад

      @@TheSmokinApe no worries 👍

  • @KC1PSK
    @KC1PSK Год назад

    I just got 50 ft of RG316. It’s a SWR nightmare. I will never use it again. 1.2 to 10 every other second.

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Sorry to hear you’re having problems with it

  • @robertmeyer4744
    @robertmeyer4744 Год назад +1

    real good. I have the Nano VNA-H4 . putting a coil in the coax buy antenna helps with common mode current. but warping threw ferrite gives more attenuation per turn. I have the M & P POTAFLEX 7 and that tested great at VHF/UHF . also coax length can be a factor at select frequency's . resonate length . don't see that much at HF unless the shield is acting as a counterpoise. I found that using a end fed half wave dipole with 49:1 UNUN. length of coax can effect SWR and RFI back to radio. this was worse on my 9:1 . longer feed line was a big help at lower frequency's . also a 1:1 after antenna and a counterpoise also works. each portable setup can tune different. nice job on coax loss . best to read data sheet before you buy. for HF RG-8X works great for 50Ft runs or less. can take some power as well. but not all RG-8X the same. ABR makes a real nice 8X type. 73's

    • @TheSmokinApe
      @TheSmokinApe  Год назад +1

      Hey Robert. I noticed more RFI with my 9:1 than the 49:1 as well. I pretty much always go the counterpoise and choke route these days 👍

  • @75ohmHAM
    @75ohmHAM Год назад

    I use 75 bc im broke, damn kids lol, also I got 1k foot box for free, and I can't see a loss great enough to make me care, I use resonant and efficient antenna

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      Using 75 is fine if you take what into consideration which it sounds like you have done. Thanks for the comment 👍

    • @GoonyMclinux
      @GoonyMclinux Год назад

      Rg11 is actually pretty good, I use it for everything.

  • @keithwilliams3028
    @keithwilliams3028 Год назад +1

    You never showed how to measure the co-ax, just the results. Video title says measuring co-ax cable loss. Get with the program and show people how to do it. This is just click bait.

    • @TheSmokinApe
      @TheSmokinApe  Год назад

      If you want me to show you have to use a NanoVNA I have videos on that as well.

    • @keithwilliams3028
      @keithwilliams3028 Год назад

      The title of the video states "Measuring Coax Cable Loss For Ham Radio Beginners" people expect to be shown , if you are not going to show what title states then a link should be given. The word measuring says that you are going to be measuring and not just showing the results.@@TheSmokinApe

    • @LanceVK6LK_AussieHam
      @LanceVK6LK_AussieHam Год назад +2

      @@keithwilliams3028😢😭. 🤦🏻🤣🤣

    • @feeatlastfeeatlast5283
      @feeatlastfeeatlast5283 Год назад +1

      @@keithwilliams3028 What are you talking about? He showed you exactly how to measure the cable loss at any frequency. You thought he was going to show you how long the coax was? You wanted to see a tape measure?