HELP understanding garmin astro/alpha dog collar frequency work mode

**ialdasor** · 28th November 2018, 01:13 PM

Hi,

I want to understand how works garmin astro alpha devices radio communication between the handheld and collar devices. I have repaired some collars and i know that there are different country collars. For example here we can see a list:

Code:

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Likewise say there some collar use frecuency 155.450, 155.475, 154.600...

My question is, how we say to the collar to use one frequency or other? Its by software or hardware? I think the software its the same for all collar (usa, spanish, france, australian...) and its by hardware but if we change id of the collar from handheld we can switch some frequencies.

Do you think that we can convert a USA collar to SPANISH for example?

And other question, i have a collar that looks swedish (dc 40s) and i tested with a frequency meter that its sending data trought 155.475 (same frequency as spanish) but i cant track it with spanish handheld. Why?

If anyone can help me...

Thank you very much and sorry for mu bad english..

**Butters** · 28th November 2018, 11:39 PM

This patcher may be what you need: [Only registered and activated users can see links. ]. Be aware that you won't get support in it's practical use here, however going by the sophistication of your information above it seems you'll not need any help in it's use.

**miroslavbl** · 29th November 2018, 10:09 AM

Hi!

I think that software is main.

There are several bits hidden in memory content witch content version and ID. I can not identify this bits.

If you can rewrite FULL memory content from one collar (device) to other, you will convert and change ID.

Devices from Croatian and Germany use same frequency (155,450 MHz) and I have information on Croatian device from Germany collar. I have tried with Alpha 100 and T5.

**ialdasor** · 3rd December 2018, 02:21 PM

Thank you very mutch Butters and Miroslav.

I know the universal patcher but i dont think that it do what i want. With this i can bypass the region limitation but i cant change the frecuence of a collar. I will test it anyway.

Miroslav: "Devices from Croatian and Germany use same frequency (155,450 MHz) and I have information on Croatian device from Germany collar. I have tried with Alpha 100 and T5."

This part its interesant, how do you move information of a croatian to germany?

Thank you very much

**Butters** · 4th December 2018, 05:27 AM

In very simple terms I believe this is what happens when a collar localized to a country [say Croatia] pairs with a German localized device receiving a GPS signal the latter country which uses the same frequency 155.450 MHz (BTW, they are commonly-used frequencies. You'll notice that Slovenia, Poland, UAE, Norway, Lithuania, Cyprus, Czech Republic, Estonia, Finland, Sweden and Slovakia all use 155.450 MHz, & 155.475 MHz too, while Austria, Latvia and Iceland also use 155.450 MHz): The devices may pair only until the tracking device recognizes from a GPS fix that it's in Germany and then will not proceed because, for want of a better expression, it's 'geofenced' by the firmware to only pair continuously within Germany with a collar identifying itself as also being localized German and that's despite the fact a 'foreign' collar is transmitting on a local frequency. What the modified patcher by AlexWhiter does of course is remove that firmware limitation so for example a US Astro/Alpha will work with a US collar anywhere in Europe. What it almost certainly likely doesn't do is allow a US device to receive a signal from an EU collar but it might allow a German device to receive a transmission from a Croatian collar on 155.450 MHz, or a Spanish device to receive from a Swedish collar on 155.450 or 155.475 MHz as examples. I'm only guessing though so perhaps you should ask the question of AlexWhiter in his Astro/Alpha regional limitation patcher thread, or just do your own test as you remarked.

I must say that this kind of chat is probably a little dangerous here and that Garmin would not look kindly on specific help being given which is probably why the author of that other thread isn't prepared to give detailed support.

**miroslavbl** · 4th December 2018, 09:53 AM

I think there are few bits somewhere in memory which define regional version. You can compare several memory contests and try to find these bits.
Main problem is that you have to have several memory contests with same software version for comparison and different regional version.

@Butters If this post against forum rules, delete that, please.

**Butters** · 4th December 2018, 11:26 AM

Not against forum rules as such to simply discuss modifying firmware. It's certainly against Garmin's End User Licensing Agreement to actually make modifications but there's absolutely no mention in the terms of their EULA about discussion of modification, it's the act of modification that is a clear breach. What i meant about this chat is that it may catch unwanted attention from Garmin if this discussion continues onto disclosing which particular bits to switch enabling a change of locale/transmit frequency in collars and it would be very courageous (as in reckless) to post modifications both from the forum rules stance but particularly because of the breaching Garmin's EULA which triggers breach of rules too. You guys might be better to continue this privately if you stop feeling comfortable discussing it openly after reading the EULA .... Just a kindly suggestion.

Code:

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To be clear there is no breach so far of either forum rules or Garmin's EULA and you can actually talk openly about modding until the cows come home, but if you start physically flipping bits in their software it might be better not disclosed.

**ialdasor** · 5th December 2018, 10:14 PM

Thanks for the suggestion. If you want you can close and delete the posts. I have to say that iam not doing any illegal thing with the collars. The problem is that arrived to me some collar from different clients with problems that they cant pair their collar to their astro handheld. I know the region limitation that Garmin installed on lastest firmware and its correct this modification because we cant use that frequencies on these regions. The problems is that collars are using same frequency but can pair. But you have explained me the raison. I have contacted Garmin too but they cant say me anything or the technigian that talk to me doesnt know.

Thanks both for the help gived me. Close/delete if you want.

Good night!

**Butters** · 6th December 2018, 12:05 AM

There's no problem with the thread as far as I can see with what's been discussed to this point however in any case I'm not a mod here.

Now that you understand the reason for differently localized device/collars using the same frequency not pairing properly you may be able to find a workaround. Good luck.