Description

Page update on 6/2/2026 ( add part 2 start date & time)

sorry i didn’t know i had my wattage meter in SWR mode anyways here is the link to the live:

https://youtube.com/live/NDiIyZg3Hcs

PART 2 on Thursday start time at 3:00pm central time!

https://www.youtube.com/live/nNOf2MwyBIU?si=KONvhFFC-2__Y95M

NOTICE: keep in mind outside temp, how many fans are used, if air conditioning is used at the repeater site, what type of enclosure case is used to hold the radios,etc will effect the results, so the results can vary from setup to setup!

Planned live video stream date is Tuesday 5/26/2026 at 6:00pm central time!!

here is the YouTube video link for this:

https://youtube.com/live/NDiIyZg3Hcs

info on radio gear setup:

The RA87 radio has built in TOT i can not turn it off, I can only set it to 10 mins!!  during my testing this seems to stop transmitting for about 1 second then it starts transmitting again in till 10 mins is up! This off time is not enough to effect the results of this test!! however as the time goes on if this off time gets longer then i will have to stop the test!

The specs in the owners manual page 19 said -20c – 60c which is -4F  –  140F so will have to see what happens!!

The plan is i will start out running the top 80mm 4,000 rpm 46.6 CFM fan which is model AFB0812SH if the temps, wattage or audio sounds bad i will turn on the bottom fan which is a 140mm 2,500 rpm with 110 CFM which is model number pro14 pro pst!! each fan has a green LED one for top fan and one for bottom fan!! This will show you which fan is running!!!

Setup video here:

https://youtube.com/shorts/27m5geM8Is8

To see picture on how temp probe is hooked up to TX radio click here

repeater rack and retevis Ra-87 mobile top fan mod if you are interested in buying this click here

(2) retevis Ra-87 mobile radios as a repeater (repeater setting in radio menu)

(1) top 80mm Fan mod that is blowing on the output I.C with radio cover off and fan will run all the time!! maybe two fans are need? We will find out!!!

temperature probe measuring temperature of the output I.C (its a small circuit) on the TX radio ( top radio)  to see how the temperature probe is mounted click here

workman wattage meter measuring wattage output of TX radio (top radio)

Wireless Thermometer which has indoor temperature =  top number is outdoor, middle current time, bottom number is indoor temp( white in color, This was moved to next to the wattage meter)

bottom radio is the receive (RX) radio

50 watt duplexer (above the power supply)

30amp power supply with built in fan ( bottom of repeater rack) power supply i am using is this one click here

SWR = about 1.265 ( tested with NanoVNA) are you using a dummy load? NO why? people don’t use dummy load when repeater is being used at a site! its hooked up to my adjusted SWR j-pole antenna, which uses my adjustable SWR j-pole antenna kit that i sell click here for that kit!!

wattage output AFTER the duplexer is about 20- 25 watts

Retevis RA-87 radio power supply is plug into a smart WiFi outlet so i am able to turn power off remotely!!

I have a private video feed to monitor radio temp,radio output wattage, indoor temp!

prerecorded message saying we are testing radio duty cycle with call sign. This message will key up the radio with NO OFF/WAIT time! duty cycle tester is plug directly into the TX radio ( top radio)

Hopefully I don’t have any hardware failures like power supply,radio,fan,etc then of course test will stop. if i see the probe temp go to high or the wattage starting to drop i will stop the test!

info on YouTube LIVE stream and video:

Length of this test is planned for “about” 12 hours! however YouTube live feed could be less do to internet,power,etc that could go out but i will try my best to keep the YouTube live going for as long as i can!! NOTE: YouTube only records/saves 12 hours of video!!

NOTE: during the live video there will be audio/sound which will be the message coming over the RA-87 mobile repeater, I will have a handheld that is tuned to the repeater freq, This handheld is directly plug into the iPad using a custom made cable! also there is about 1 min delay meaning when something changes on my end (i.e wattage meter reading,etc) it will be about 1 min before you see it on your end!!!

NOTE: if all goes well YouTube will save this as a video so it can be viewed in the future!! NOTE: YouTube only records/saves 12 hours of video!!

any question send an email to:

[email protected]

if you would like to donate to help with future test like this send whatever you want using zelle, info on how to send using zelle here:

https://www.gmrstwowayradio.com/forum/viewtopic.php?t=175

Thank you!