Ski Hill - Cross band Repeater Set Up

[R8000]

When I transmitted on one of the HT1 on UHF, HT2 that is suppose to listen for VHF from mobile rig, seemed to be receiving the UHF signal directly from the HT1.

What is going on? Am I getting receiver overload because both HT’s are two close to each other even though they are listening on a different Frq band?

You should look at post #9. This was the correct answer for what you wanted to do. What you are wanting to accomplish requires a real repeater NOT a cross band repeater.

Cross band repeaters have a purpose. But for what you want to accomplish, it is not the right solution.

 

[prcguy]

Yes, keep them some distance apart or they can overload and cause the problem you are seeing.

When I transmitted on one of the HT1 on UHF, HT2 that is suppose to listen for VHF from mobile rig, seemed to be receiving the UHF signal directly from the HT1.

What is going on? Am I getting receiver overload because both HT’s are two close to each other even though they are listening on a different Frq band?

 

[Ve2nlm]

Yes, keep them some distance apart or they can overload and cause the problem you are seeing.

Thanks... this is what I thought was happening! I will test it this weekend on a ski hill when both HT's will be quite some distance apart. It will be more of a realistic test then.

 

[Ve2nlm]

You should look at post #9. This was the correct answer for what you wanted to do. What you are wanting to accomplish requires a real repeater NOT a cross band repeater.

Cross band repeaters have a purpose. But for what you want to accomplish, it is not the right solution.

Not exactly. My HT channel is set to a split frequency. It will TX on UHF and RX on VHF. This is why I was not understanding what was going on...

I even tested it with the CrossBand rpt turned off by having HT1 set to TX/RX on the VHF frequency and the other HT2 set to TX/RX on the UHF frequency. HT1 was transmitting on VHF and HT2 was picking it up if I was within 20 meters from it. I guess this is what RF overload is!

Note that I was testing this with Baofengs f8HP set to 8watts. Maybe the rx selectivity of these radios are not so great. I am hoping for better results with my TERA radios.

 

[TampaTyron]

To cover up this issue (ie mask the behavior), you could try split PL tones on the tx and RX freqs. This may cover up the overloading behavior. TT

 

[kayn1n32008]

Not exactly. My HT channel is set to a split frequency. It will TX on UHF and RX on VHF. This is why I was not understanding what was going on...



I even tested it with the CrossBand rpt turned off by having HT1 set to TX/RX on the VHF frequency and the other HT2 set to TX/RX on the UHF frequency. HT1 was transmitting on VHF and HT2 was picking it up if I was within 20 meters from it. I guess this is what RF overload is!



Note that I was testing this with Baofengs f8HP set to 8watts. Maybe the rx selectivity of these radios are not so great. I am hoping for better results with my TERA radios.

If you insist on using the Baofeng, cut it back to 4 watts. Save your battery. 8 watts won’t get you any farther than 4 watts.

Better would be to use non-Chinese junk.


Sent from my iPhone using Tapatalk

 

[nd5y]

Note that I was testing this with Baofengs f8HP set to 8watts. Maybe the rx selectivity of these radios are not so great.

Baofengs have extemely poor receivers that desense and overload easily.

 

[Lauri-CoyoteFrostbite]

Ve2, what you are experiencing is a de-sensing issue. Even though those two handhelds are divergent in not only frequencies but bands, the proximity of a broad band'd receiver to any transmitter is going to desense (ie: 'squawk.)
Get someone to help you test this out- someone that can talk into your machine at a distance. I think you will find that things are far better than they seem.
.
Earlier (post) I mentioned my neighbor's machine- its an ancient Icom 2400 he keeps in a shed on the side of a mountain at 10-11,000 feet. It crossbands 146.52 to a 420-422 freq. (I forget exactly, but its in the low end of the 70cm band)- He sez its <10 Watts each band- it covers line of sight out to 70 miles with separate Ringo Ranger 5/8 wave verticals.
.
Have fun- you're on the right track
.
.

Lauri
.

 

[Ve2nlm]

Ve2, what you are experiencing is a de-sensing issue. Even though those two handhelds are divergent in not only frequencies but bands, the proximity of a broad band'd receiver to any transmitter is going to desense (ie: 'squawk.)
Get someone to help you test this out- someone that can talk into your machine at a distance. I think you will find that things are far better than they seem.
.
Earlier (post) I mentioned my neighbor's machine- its an ancient Icom 2400 he keeps in a shed on the side of a mountain at 10-11,000 feet. It crossbands 146.52 to a 420-422 freq. (I forget exactly, but its in the low end of the 70cm band)- He sez its <10 Watts each band- it covers line of sight out to 70 miles with separate Ringo Ranger 5/8 wave verticals.
.
Have fun- you're on the right track
.
.

Lauri
.

thanks Laurie! Will hopefully test this tomorrow on the hill. [emoji3]

Sent from my SM-G930W8 using Tapatalk

 

[robertmac]

In Canada 70 cms band is from 430-450.

 

[Ve2nlm]

In Canada 70 cms band is from 430-450.

ya...definitely must follow the rules. I tested this on the skihill today. Something did not work right...[emoji53] i will report back soon.

Sent from my SM-G930W8 using Tapatalk

 

[Ve2nlm]

ya...definitely must follow the rules. I tested this on the skihill today. Something did not work right...[emoji53] i will report back soon.

Sent from my SM-G930W8 using Tapatalk

I tested this out on the ski hill on saturday,
So this did not work out as planned for some reason that I am not sure of at this point.

The reception of the HT's was very poor with very distorted audio including static.

While both HT's were roughly 500 meters away from each other and the same distance from the Cross Band mobile rig, audio had a lot of static and sometimes did not even open the squelch.

-Everything was line of sight
-Mobile Radio was set to 10 watts.
-My HT's were set to 4 watts.
-The frequencies (VHF/UHF) chosen were not a direct harmonics of each other.
-Beautiful sunny day
-Mobile antenna was set ontop of my car roof

My hypothesis for this happening are:

1- my HT antennas are really really poor at resonating VHF signals
2- HT frequencies were NFM while the Mobile crossband was FM
3- The mobile cross band rig had a hidden frequency step of 0.6 Mhz in the programming


What do you guys think?

Thanks!

 

[kayn1n32008]

I tested this out on the ski hill on saturday,

So this did not work out as planned for some reason that I am not sure of at this point.



The reception of the HT's was very poor with very distorted audio including static.



While both HT's were roughly 500 meters away from each other and the same distance from the Cross Band mobile rig, audio had a lot of static and sometimes did not even open the squelch.



-Everything was line of sight

-Mobile Radio was set to 10 watts.

-My HT's were set to 4 watts.

-The frequencies (VHF/UHF) chosen were not a direct harmonics of each other.

-Beautiful sunny day

-Mobile antenna was set ontop of my car roof



My hypothesis for this happening are:



1- my HT antennas are really really poor at resonating VHF signals

2- HT frequencies were NFM while the Mobile crossband was FM

3- The mobile cross band rig had a hidden frequency step of 0.6 Mhz in the programming





What do you guys think?



Thanks!

Your biggest issue is going to be trying to receive a wide band signal using narrow band filters. It will sound like crap. A hidden offset on the VHF side will also cause problems.

If you insist on using those Baofengs, get better antennas, they pretty much are dummy loss on VHF


Sent from my iPhone using Tapatalk

 

[nd5y]

Putting a better antenna on a Boafeng will probably make it worse.

 

[kayn1n32008]

Putting a better antenna on a Boafeng will probably make it worse.

Good point.


Sent from my iPhone using Tapatalk

 

[Ve2nlm]

I am using TERA 505 radios. They actually work very well simplex on VHF and UHF.

 

[krokus]

I tested this out on the ski hill on saturday,
So this did not work out as planned for some reason that I am not sure of at this point.

The reception of the HT's was very poor with very distorted audio including static.

While both HT's were roughly 500 meters away from each other and the same distance from the Cross Band mobile rig, audio had a lot of static and sometimes did not even open the squelch.

-Everything was line of sight
-Mobile Radio was set to 10 watts.
-My HT's were set to 4 watts.
-The frequencies (VHF/UHF) chosen were not a direct harmonics of each other.
-Beautiful sunny day
-Mobile antenna was set ontop of my car roof

My hypothesis for this happening are:

1- my HT antennas are really really poor at resonating VHF signals
2- HT frequencies were NFM while the Mobile crossband was FM
3- The mobile cross band rig had a hidden frequency step of 0.6 Mhz in the programming


What do you guys think?

Thanks!

1) Did you use 70cm or 2m from handheld to repeater?

2) Do not mix NFM and FM. Pick whichever one sounds better on those radios, and use it for both sides. (For ham gear, FM is probably going to be better.)

3) What do you mean the 0.6 MHz step? That sounds like the automated repeater offset for 2m. These should be two distinct freqs, one in each band.



Sent using Tapatalk

 

[Ve2nlm]

1) Did you use 70cm or 2m from handheld to repeater?

2) Do not mix NFM and FM. Pick whichever one sounds better on those radios, and use it for both sides. (For ham gear, FM is probably going to be better.)

3) What do you mean the 0.6 MHz step? That sounds like the automated repeater offset for 2m. These should be two distinct freqs, one in each band.



Sent using Tapatalk

1- i used a TX of 70cm on the handhelds due to me having short antennas.
2m was the RX on the handhelds from the cross bander.

2- i had NFM set on the HT which sounded great when using a simplex frequency without the cross bander. My Cross bander was using FM.

3-I thought my cross bander was forcing a offset because in Chirp it says 0.6 in the offset column... i looked into it last night and it was not set to ON in the chirp program so the offset does not seem to be active.



Sent from my SM-G930W8 using Tapatalk

 

[Ve2nlm]

Just so the intent is clear. I sketched something up in MS Paint.
In this example, the cross band repeater is line of site with both HT's
Also, both HT's may also be line of site from each other at any given moment.

 

[RFI-EMI-GUY]

Just so the intent is clear. I sketched something up in MS Paint.
In this example, the cross band repeater is line of site with both HT's
Also, both HT's may also be line of site from each other at any given moment.

You need to simplify the problem.

Have you confirmed that:

1) Each portable can communicate reliably both ways with the Crossband repeater on its local mike and speaker. Do this with and without repeat engaged to gauge the desense if any. Do this with someone else operating the portable at various distances from the mobile.

2) Does the Crossband repeater actually transmit alternately on the V and U frequencies? Is audio and CTCSS passed?

3) Turn off the repeater and ensure that the portables cannot hear each other on the U V pair. Turn off any scan feature. They should not hear each other.

4) Turn on the repeater and test with two portables a reasonable distance from each other and the repeater, they should hear each other.


Sent from my SM-T350 using Tapatalk