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WRUT935

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Posts posted by WRUT935

  1. Getting into a repeater, but not getting a return

    in Technical Discussion

    Posted

    I know this is an old thread but of interest as I am experiencing similar issues with the OP. I do hear the reply’s from the other stations on the repeater but often with lots of static. They say I am coming in clear but they come in weak, with lots of static. I have raised my Ed fong GMRS antenna to my max (2 story house chimney stack plus a 10 foot pole). I have tried two radios ( Wouxun KG 1000G + and a Kenwood KT 8180). Yes certain days and time it is all clear both RX and TX. I would think that my TX will be more of an issue than my RX.  I do understand my geo challenge with hills around me to the direction of the repeater.  Moving to yagi may potentially help but will leave me directional unless I also invest on a rotator. 73s

  2. Base Station Versus Handheld with Aplifier

    in Technical Discussion

    Posted

    I used the btech amp. It is rated at 40 amps but with the increased output of the Wouxun HT I was measuring over 45 watts at times. Be careful not to transmit on the FRS and low GMRS channels, else you are blasting them and not following regulations. If you don’t use the frs channels, you can just turn off the transmit on those just like mobile. 

     

  8. New Nagoya Antennas for HTs

    in Equipment Reviews

    Posted

    Ya, I saw that, I dont like that they only offer it with SMA Female which means you have to add a converter for other radios like the Wouxuns,  I would be nice to have it on BNC without the need for another adapter.  With this length, using a BNC will make it easier to remove and or to swap with a shorter antenna.  The 15 inch 771G is a bit long to walk around with but has given me a noticeable performance boost.

  11. Dummy Load showing 1.7 SWR

    in Technical Discussion

    Posted

    I just for this 50W 50 ohm dummy load.  XRDS-RF from Amazon.  I directly connected it to my SureCom meter, no cables and no adapter needed. I keyed up and read both wattage and SWR, the  SWR shows 1.7 which is higher than what I get through my outside antenna with 45 feet of cable!  Is this just a bad dummy load or am I missing something.  I expect 1.1.  I measured the resistance using a digital ohm meter and it read 49 ohms.  

    Why am I checking SWR?  To use the dummy load to measure line loss of the cable.  Professor Ed Fong told me it would be  good reference to measure the SWR introduced by the cable and measure again with the antenna.  This way, you can tell what is contributing to the overall value.

    I know there are a lot pricier dummy loads, is this brand/unit bad?

     

  16. Thoughts on BTECH U25 AMP?

    in Equipment Reviews

    Posted

    On 12/20/2022 at 1:40 AM, wrtq652 said:

    I can see from the post above a Standing Wave Ratio (SWR) meter wasn't available at the time and checking the SWR was suggested. It would be worth taking a look at the SWR when a meter becomes available.

    I'm curious to know if anyone is checking the Standing Wave Ratio (SWR) between the BTECH-U25 AMP and the antenna after swapping the feed line from the handheld to the BTECH-U25?

    Having an antenna with a low SWR would allow the most output power to be sent through the antenna.  I'm curious as to what reflected power the BTECH-U25 is able to handle and if it has any protection circuitry built into it, for example to reduce the output power if the reflected power at the transmitter is too high.

    It's reasonable to say a high reflected power for a handheld is going to be under 5 watts, as we go up in power closer to 40W, the reflected power of a poor SWR match may be enough to damage the amplifier.  A properly matched antenna/feed line is going to be important as the wattage increases so the reflected power will not damage the finals of the amplifier.  (Also be sure the SWR meter in use is rated for the GMRS band (~462MHz - ~468MHz) / (UHF)).

     

    A good description of safe ranges for radios SWRs is posted on the CB World website.  The article describes best practices for SWR common to antennas.

    SWR 1.0-1.5: The ideal range!

    SWR 1.5 - 1.9: There's room for improvement, but SWR in this range should still provide adequate performance.

    SWR 2.0 - 2.4: While not good, this likely won't damage your radio with casual use.

    SWR 2.5 - 2.9: Performance in this range will be noticeably decreased, and you might even damage your radio if you transmit frequently and for extended periods.

    SWR 3.0+: Performance will be severely affected, and you're likely to damage your radio with extended transmission use.

     

    The second item worth mentioning is having a stable input voltage and power delivery for the amplifier power supply.  The BTECH website lists the power draw at "13.8 VDC (±15%), 5.5 A maximum" (BTECH, 2022), another test indicates 13.6V 30A power supply was just under 6A (Miklor, 2022).  Two of the most common problems with installing radios and amplifiers are SWR and proper power supply voltage (Shannon, 2022).  Testing the voltage at the power supply to the amplifier to be sure it's receiving the proper voltage at 13.8 volts would allow the amplifier to deliver the most power to the transmitted signal. 

    There's a good discussion of the input voltage to the radio, related to a different transmitter, and how a 3.5volt to 4 volt drop was seen when transmitting at the radio/amplifier side of the connection contributing to undesirable transmitting results (Spatz, 2022).

    A direct to battery connection would make it more likely the amplifier is operating at the correct voltage, at least the power connection would be isolated to power draw from the amplifier.  A fused power connection directly to the battery and into the passenger compartment or to where the BTECH-U25 amplifier is located would be ideal.  The connection to the battery could have a cigarette lighter input adapter attached to it, to make the install of the BTECH-U25 easier to plug in or move to another location.

     

    Thanks @WRVG593 for sharing your install story and I wish you the best in getting the BTECH-U25 installed. Keep us updated if you decide to move the amplifier again and how it all works out for you! I'm curious to know how the 2nd choice for the install location works out if you decide to go that route?

     

     

    References:

    BTECH AMP-U25 UHF analog amplifier. BaoFeng Radios. (2022, December 12). Retrieved December 19, 2022, from https://baofengtech.com/product/amp-u25/

    CB World. (n.d.). What is SWR and why is it SO important? . CB World. Retrieved December 19, 2022, from https://www.wearecb.com/what-is-swr.html

    Miklor, J. (n.d.). Review btech power amp. Miklor. Retrieved December 19, 2022, from https://www.miklor.com/COM/Review_DMR-Amps.php

    Shannon, S. (2022, December 19). KG-XS20G Plus problem. myGMRS.com Forums. Retrieved December 20, 2022, from https://forums.mygmrs.com/topic/4932-kg-xs20g-plus-problem/#comment-48811

    Spatz, M. (2022, December 19). KG-XS20G Plus problem. myGMRS.com Forums. Retrieved December 20, 2022, from https://forums.mygmrs.com/topic/4932-kg-xs20g-plus-problem/#comment-48819

     

    I have been using my BTECH U25 with my Wouxun KG-UV9G Pro (5+ watts) for a few weeks now.  It is connected to an Ed Fong antenna on my roof with 45 feet of KMR400 (thick cable similar to LMR 400). 20A/30A peak  PS.   I have a Surecomm SWR/Power meter connected.  SWR without the AMP (direct connected not bypassed) is less than 1.1, as low as 1.01.

    SImplex:

    GMRS 19 = 1.2 SWR Watts = 48W

    Repeater Channels:

    1.3 SWR = 46 W

    Highest reading I got was 49W.

    I have a Wouxun KG-20G which I alternate with the BTech Amp setup using the same antenna.  Since I can only TX at 20W, some repeaters could barely hear me.  I am challenged with a quarry and a mountain range on my SW.  The extra wattage does help and the BTech mic seems tx much louder, I am told by those who I have done test with switching radios.

  18. New GMRS Mobile Radio - Wouxun KG-XS20G

    in Equipment Reviews

    Posted

    Just got the replacement mic from buytwoway. The new mic has the same issue as the first.  I wrote the vendor back and hopefully will hear tomorrow. I hope I just got another bad mic and that the radio is not defective.  
     

    those who own the kg-xs20g plus, have you tried to switch from spk1 to spk2 and is the mic speaker working properly? 

  19. KG-XS20G plus problem

    in Technical Discussion

    Posted

    I have the same model from buytwoway. I experienced it once but mine is connected to a PS, voltage on both the radio and a digital voltmeter shows 13.7 Volts and SWR is less than 1.2. 
    I am having speaker 2 issues, the one on the mic. They already sent me a replacement mic and the problem persists, I just hear a little crackling sound out of spk 2.  I hope Wouxun workmanship is doing down. 

  23. New GMRS Mobile Radio - Wouxun KG-XS20G

    in Equipment Reviews

    Posted

    Thanks to Randy's discount code, I got my unit a few days ago.  An early xmas gift from my wife.  I have a Wouxun KG-UV9-Pro from BSR.  Both radios a very good.  The 20+ watts makes a big difference for me due to the hills and Mt. Diablo near me.  I was able to connect to the repeater in Sunol and was able to converse with clarity.  I paired it with a pyramid 6 amp PS. I have an Ed Fong antenna on my roof/side of the house (HOA) with a 25 foot KMR 400 (amazon) cable.  My SureComm digital meter shows upto 22 Watts out with SWR of 1.18. So far no issues.  There was one weird anomaly this afternoon  that the tones for one of the repeaters got set to off, hence it can't talk and hear on that repeater.  Watch Randy's videos on this model to get to additional info, he has one when it first came out and a follow up when it went "plus".  The free Wouxun software makes it easy to change setting but it does NOT have the ability to import/export.  My UV9-Pro has tons of channels and I can't port them over, not even copy and paste using the Wouxun software.  The RT systems software (around $25) does not show one for the xs20G. The Wouxun Commander for the XS20G does not recognize the file output from the UV9-pro.

    WRUT935/Benjo

      

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