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SVTwilight · 21-02-2012, 20:22

I am putting an 802 on my boat.

Anyone have any experience with the Pactor 4? Am I better off with the Pactor III?

Regards,

Todd

Tashtego · 22-02-2012, 20:03

I am told that PACTOR 4 is illegal inm the US as it exceeds the data rate limit from the FCC

SoonerSailor · 23-02-2012, 06:24

Granted that the bandwidth of Pactor4 may make it unqualified for US licensed amateur radio operators on the ham bands, but would it still be OK on the marine radio bands for use with SailMail for example?

I also wonder if the new modem might work better on Pactor3 than the older modem? Probably not, but its a thought.

Finally, for Pactor4 to be of benefit, I suspect you will be challenged to find fixed stations that support it even on frequencies where it is permitted. I wouldn't be surprised if it will take a while for this technology to propagate to a useful number of stations due to the cost.

Does anyone have a better handle on these issues?

**btrayfors** · 23-02-2012, 06:58

I believe Pactor 4 (Dragon) is OK on the marine bands, e.g., SailMail.

Gary @ Dockside Radio has been running some tests with a West Coast station, both using P4 modems. Last I heard, they were getting about twice the speed of P3.

You might ask him for details: Pactor-II/III Radio Modem sales, FCC License filing, Marine SSB & HAM Radio Net schedules &amp frequencies.

Bill

Auspicious · 23-02-2012, 09:36

P4 is fine on marine bands. The issue in the amateur bands is baud rate, not bandwidth.

To my knowledge none of the commercial services (Sailmail, CruiseEmail, and ShipCom) are upgrading to P4 yet.

For cruisers sailing in the Far East using Winlink to EU and Asian shore stations P4 may make sense. For commercial marine and US domestic connections I would not spend the extra money today.

SoonerSailor · 23-02-2012, 18:47

Where can I find information on the baud rate limit on ham bands? I can find reference to a 500 Hz bandwidth limit for data modes below 30 mHz in Part 97, which would rule out even P3, but nothing further.

SVTwilight · 23-02-2012, 23:45

Thanks everyone for the input. It would appear the safe bet is the Pactor 3

Todd

Auspicious · 24-02-2012, 09:09

Quote:

Originally Posted by SoonerSailor

Where can I find information on the baud rate limit on ham bands? I can find reference to a 500 Hz bandwidth limit for data modes below 30 mHz in Part 97, which would rule out even P3, but nothing further.

There is a 300 baud (symbols / second) rate limit for HF as well. It's in Part 97 somewhere. I did a real fast Google but didn't turn up the citation. If you get on one of the Yahoo Winlink groups someone will be able to cite chapter and verse for you. If you can't find it send me a PM and I'll get the citation for you.

**dandrews** · 25-02-2012, 18:45

Quote:

Originally Posted by SoonerSailor

Where can I find information on the baud rate limit on ham bands? I can find reference to a 500 Hz bandwidth limit for data modes below 30 mHz in Part 97, which would rule out even P3, but nothing further.

You can google FCC part 97. Then examine part 97.305 and 97.309. The limit on some bands is actually 19.6 kb. It depends on the freq band you plan to use.

Don
N1FVB

ewitts · 22-04-2012, 09:36

I heard that the p4 improves p3 performance. I was just updating my frequency list and there are a quite a few hams supporting p4 in canada and some in Mexico. I guess you can access these using p4 when maritime mobile out of U.S. waters. What do you guys think?

Auspicious · 22-04-2012, 09:51

Quote:

Originally Posted by ewitts

I heard that the p4 improves p3 performance. I was just updating my frequency list and there are a quite a few hams supporting p4 in canada and some in Mexico. I guess you can access these using p4 when maritime mobile out of U.S. waters. What do you guys think?

I'm still unclear on the legalities of P4 by US flag boats even outside of US waters. I'm not saying you can't but I haven't seen anything with original source material from a credible source.

Sailmail is well underway upgrading their shore stations to P4 and the marine frequencies are not subject to the 300 baud symbol rate that restricts the use of P4 on amateur frequencies.

Every indication I have seen is that the faster, more powerful processor in the P4 Dragon and the improved algorithms in that unit do indeed result in higher average throughput than the older PTC-II units.

I don't have one, but I suspect my next order to Farallon will include an extra one for me. *grin*

MarcHall · 22-04-2012, 13:01

From my reading the Pactor 4 is legal on Marine Bands and Sailmail has at least 2 sites where they have P4-Dragons in use.

The P4 Dragon is also compatible with Pactor III, so if I was the market for a new Pactor modem I would look seriously at the P4 Dragon. Sailmail limits its users to the amount of time the system can be used each week (90 mins per week) so having a modem that is capable of the twice the speed is either going to provide you with more email bandwidth or less connect time to deliver the same amount of mail as on Pactor 3. The other benefit is the reduced power consumption for sending and receiving the traffic on the boat.

Marc Hall
Crazy Fish, Crealock 37, Hull 207

Olorin · 22-04-2012, 13:21

I just installed the M802 and the P4 Dragon. I get twice the throughput using P4 than I do with P3.
As I plan on buying my equipment once and keeping it forever, I went for the latest and greatest.
No doubt in 20 years the P15 Hyper-Dragon will deliver embarrassingly fast data rates.

ewitts · 22-04-2012, 16:04

Quote:

Originally Posted by Auspicious

I'm still unclear on the legalities of P4 by US flag boats even outside of US waters. I'm not saying you can't but I haven't seen anything with original source material from a credible source.

Sailmail is well underway upgrading their shore stations to P4 and the marine frequencies are not subject to the 300 baud symbol rate that restricts the use of P4 on amateur frequencies.

Every indication I have seen is that the faster, more powerful processor in the P4 Dragon and the improved algorithms in that unit do indeed result in higher average throughput than the older PTC-II units.

I don't have one, but I suspect my next order to Farallon will include an extra one for me. *grin*

I found a link with that info Maritime Mobile Operation in International Waters
So it states you are under your countries rules in international waters, but reciprocal agreements are really easy most places, Mexico being a little sticky but is getting better. So I think I might be looking to up grade myself.