Something funny with my radios

[WSEE770]

I have two baofeng uv9g radios.  I have programmed them both with the correct tones for all the repeaters in the area.  I can transmit and receive on simplex between the two fine, and when using a repeater, I can work it just fine and talk and listen, but the other radio tuned to the same channel will not pick up that radio.  Is there something I'm missing besides a more expensive radio?  

I took them both to six flags in bowie maryland and on simplex channel 1 they worked perfectly. I can work Towson repeater from most everywhere I go, but when I'm on repeaters these radios don't communicate with themselves, and I'd really like them to for use with my wife as intended.

[WRXL702]

Cheaper non commercial radios do not have the receiver front end filtering, as do commercial radios. So when you are transmitting to a repeater on one unit, & your 2nd unit is too close - Your 2nd unit's receiver is being de-sensitized by the transmitting unit & not receiving the repeater output.
Depending on the manufacturer, a 50 yard separation should let you receive the repeater transmission, on the 2nd unit.

This will not be noticed when talking simplex, as you are communicating radio to radio directly, regardless of close proximity. 

[WRXL702]

In Simplex Mode, Your Radios Will Transmit & Receive At 462.600 MHz Using Correct CTCSS Or DCS As Needed.
When Connecting To A Repeater, Your Transmit Frequency Should Be 467.600 & Your Receive Will Be 462.600, Using The Correct CTCSS Or DCS. This Called The + 5MHz Offset.  A Repeater Receives Transmissions At 467.600 & Re-Transmits At 462.600 MHz. 
 

As For The Squelch Tail (Tone) - Not Sure If You Are Meaning An Actual Squelch Tail, Which Is Controlled By The Reverse Burst Squelch Setting On A Repeater - That You Cannot Program Or Control.
Or A "Squawk" Which Is A MDC Type Of Identification Tone Which Is Not Available On Your Units, & Only Available On Commercial Radios, Which Are Programmed On The Individual Radios.

[SteveShannon]

6 hours ago, WSEE770 said:

I took them both to six flags in bowie maryland and on simplex channel 1 they worked perfectly. I can work Towson repeater from most everywhere I go, but when I'm on repeaters these radios don't communicate with themselves, and I'd really like them to for use with my wife as intended.

702’s answer about desensing might be all that it is, but I think it’s more basic than that. 

When you’re using a repeater and transmitting from radio A on the repeater channel, you’re transmitting on one frequency and listening on another that’s 5 MHz lower. So, if radio B is set to receive the repeater it will not receive radio A directly.  Radio A is transmitting on one of the 467 MHz main channels and radio B is listening to the repeater output on the corresponding 462 MHz main channel.

You might be able to tune radio B to receive the repeater input frequency, but then you won’t hear the repeater output.

 

[WRXP381]

I run a fleet of uv9 radios I work repeaters all day every day.  I have never had desensitizing.  I can hold a radio in each hand and talk in the to a repeater and hear on the other radio.  
 

im getting Shannon is right in some way. I’d bet this is user error/expecting something different than what reality is.  Also check squelch on both radios one may be set higher. 

[WSEE770]

On 9/15/2024 at 7:46 AM, SteveShannon said:

702’s answer about desensing might be all that it is, but I think it’s more basic than that. 

When you’re using a repeater and transmitting from radio A on the repeater channel, you’re transmitting on one frequency and listening on another that’s 5 MHz lower. So, if radio B is set to receive the repeater it will not receive radio A directly.  Radio A is transmitting on one of the 467 MHz main channels and radio B is listening to the repeater output on the corresponding 462 MHz main channel.

You might be able to tune radio B to receive the repeater input frequency, but then you won’t hear the repeater output.

 

I was talking about two seperate scenarios.  The radios worked fine on simplex, but when the uv9gs were both set to 462.600, they seemed to have desensed.  Now my problem is my gm21 is either not hitting 462.600, or is setup wrong.  I've got the tone set to the correct one for t-ctcss for all my local repeaters, and I can hear the repeater morse identifiers, and I can transmit to the uv9gs on the same repeater channels, but people claim to not hear me on 462.600 from the gm21.  I might send it back if when I go outside it cant hit towson.  I don't need a color screen that bad, I just ordered it because it was on sale and could get here sooner than a uv9g.

[WSEE770]

I just ended up sending back the gm21 for a uv9g, and they all work fine.  Thanks for your help.

[WSEE770]

On 9/15/2024 at 8:24 AM, nokones said:

Typical characteristics of one cheap chinese junk POS radio desensing another cheap Chinese junk POS radio in close proximity.  Real radios in most cases may be a little statically depending on the signal-to-noise-ratio, but at least you would be able monitor the traffic.

Whether they are icoms, kenwoods, or baofengs, gmrs radios for the most part all use the same channels.  Not much advantage is gained with a fancy radio in untrained hands.  I loan out my radios for social outings, so they need to be durable and cheap in case of mishaps.  I'll be fancy with my laptop though.  Have a real one of those.  alienware m16r2.  When I get my technician ticket I'll look into getting something nicer for ham.  But I'd wager that baofeng makes and sells far more radios than the fancy guys, and there is a reason for it.

[wayoverthere]

2 hours ago, WSEE770 said:

Whether they are icoms, kenwoods, or baofengs, gmrs radios for the most part all use the same channels.  Not much advantage is gained with a fancy radio in untrained hands.  I loan out my radios for social outings, so they need to be durable and cheap in case of mishaps.  I'll be fancy with my laptop though.  Have a real one of those.  alienware m16r2.  When I get my technician ticket I'll look into getting something nicer for ham.  But I'd wager that baofeng makes and sells far more radios than the fancy guys, and there is a reason for it.

It really comes down to your use case. If the cheap radio has the features you want, and isn't having desense issues, (or it's less of an issue and you want less expensive handouts ), you're golden. If not, time to upgrade.

I have a good mix of radios (from the uv5r to vertex and Motorola), and played with some real world testing along the way. Sitting in the same spot, be it on the windowsill or on the mountain by the repeater sites) I've seen hands on where one is receiving while the the other is not, be it poor sensitivity in one case, or desense in the other. On the mountain (in the vicinity of tv, FM radio, and repeater sites), the uv-5r was receiving nothing, while the little yaesu ft4x was still able to use the close by repeater.

When harbor freight will do the job, it may not be necessary to spend the extra money on snap-on.

[WRXB215]

2 hours ago, WSEE770 said:

Not much advantage is gained with a fancy radio in untrained hands.

In some cases it may be a disadvantage. It has been pointed out before that in the heat of an emergency situation a complex radio in the hands of a new user is a bad idea.

[SteveShannon]

On 9/19/2024 at 11:43 PM, WSEE770 said:

Ok.  I just read about desensing.  Makes sense.  But now I have a problem with my new gm-21.  I can hear the repeater, and I've programmed the right tones, but people can't hear me.  The manual is of no use, and youtube has like one video on this radio since it's so new and it's from gadget talk youtube channel.  He's great, but he didn't go into repeater programming for this unit, and the box didn't include a programming cable, so I will need to program on the unit itself.  Does anyone have a baofeng gm21 and know how to program a repeater so I can get the tail squelch tone at the end of the transmission?  That way I will know if I'm hitting it.  I'm trying to hit towson, md from pasadena, md and can always hit it on my uv9g.

Unless you have enabled squelch tail elimination, It’s mostly up to the repeater programming whether you hear a squelch tail. Not all do. 
As long as you’re within range for your output power, on the repeater channel, and transmitting the right tone there’s really nothing else to prevent you from activating the repeater. 

[WRXL702]

Receiver de-sense is a common problem when there is a lack of receiver front end filters. Distance is also relevant for the transmitting / receiving radio to the repeater. If at the repeater tower site - for sure the repeater will & should be heard on a HT in the other hand. But at further distances, several miles away from the repeater, a cheaper radio without additional front end filtering can & most likely will be de-sensitized by another in close proximity transmitter - especially when only 5 MHz away.

[WSEE770]

Ok.  I just read about desensing.  Makes sense.  But now I have a problem with my new gm-21.  I can hear the repeater, and I've programmed the right tones, but people can't hear me.  The manual is of no use, and youtube has like one video on this radio since it's so new and it's from gadget talk youtube channel.  He's great, but he didn't go into repeater programming for this unit, and the box didn't include a programming cable, so I will need to program on the unit itself.  Does anyone have a baofeng gm21 and know how to program a repeater so I can get the tail squelch tone at the end of the transmission?  That way I will know if I'm hitting it.  I'm trying to hit towson, md from pasadena, md and can always hit it on my uv9g.

[nokones]

Typical characteristics of one cheap chinese junk POS radio desensing another cheap Chinese junk POS radio in close proximity.  Real radios in most cases may be a little statically depending on the signal-to-noise-ratio, but at least you would be able monitor the traffic.