Seimac ProFIND DF-500P

[Eclipse]

Don't do it if you can't afford to wait MONTHS for L-Tronics (which is, I think, some guy working out of his home) to even look at it.  I sent one in for service in late March and it STILL hasn't been looked at it yet.  I called a couple of weeks ago and was told, "It's here but it will be a while before I get to it."

That'd be my concern - dump the unit's money in this and then it's a doorstop and we're worse off then before.

Plus I'd probably be bidding against a bunch of you mugs!

[LTC Don]

It would seem to me, that with the explosion of Bluetooth devices, that someone could:

Take an L-tronics switch box (the little blue switcher unit on the mast)(as an example), along with the aerials, mate that to a Bluetooth transceiver, which would then communicate with a smartphone (android or iphone) app that would have a compass display along with signal direction and strength info and whatever else useful bells and whistles. 


https://www.youtube.com/watch?v=NSC4Y8yA-jY


https://www.youtube.com/watch?v=aP4tO_sVIpI


https://www.youtube.com/watch?v=8Wzb1mgZ0EE


Semi-Related with ADS-B
https://www.youtube.com/watch?v=HS38q3YXsY4  <imagine a left/right Bluetooth dongle paired with an android phone with Google Maps functionality.  Cool stuff.

Previous episode to the above:
https://www.youtube.com/watch?v=gjYfOanm0-c

[Eclipse]

Hmmm...

http://www.dopsys.com/index.html

This seems to be in the right range.

[Майор Хаткевич]

Don't do it if you can't afford to wait MONTHS for L-Tronics (which is, I think, some guy working out of his home) to even look at it.  I sent one in for service in late March and it STILL hasn't been looked at it yet.  I called a couple of weeks ago and was told, "It's here but it will be a while before I get to it."

That'd be my concern - dump the unit's money in this and then it's a doorstop and we're worse off then before.

Plus I'd probably be bidding against a bunch of you mugs!

When the Pineda Die/Proof coin was posted on the FB history page, I figured the same thing. Got both real cheap.

[LTC Don]

Hmmm...

http://www.dopsys.com/index.html

This seems to be in the right range.

I >think< I've seen that site before.  This document is almost three years old, and they went with TCP/IP, but today I think Bluetooth is the better way to go and the whole thing could be greatly simplified with a dongle as shown on the Hak5 videos I posted:

http://www.dopsys.com/appnotes/A%20Simple%20Homing%20Direction%20Finder%20Using%20a%20DDF7001%20and%20an%20Android%20Device.pdf

But that they have an app is a great start as proof of concept.

[Holding Pattern]

So a raspberry pi, a R280T, and a 4:1 RF switchboard walk into a bar...

And it seems someone has already built a proof of concept called RasHAWK. I've reached out to the designers for their thoughts on using their work for this purpose. I've got rpi boards and R280Ts laying about, so the initial cost will be low to build something like this.

[Spaceman3750]

So a raspberry pi, a R280T, and a 4:1 RF switchboard walk into a bar...

And it seems someone has already built a proof of concept called RasHAWK. I've reached out to the designers for their thoughts on using their work for this purpose. I've got rpi boards and R280Ts laying about, so the initial cost will be low to build something like this.

I've always wondered if this was possible. At it's heart, the L-Per just measures the signal strength on each antenna and shows you the difference... Should be simple enough on a Pi.

[sardak]

Interestingly I found an outfit called MetOcean still manufacturing a similar device for buoy and other marine location that looks like the same case and a similar faceplate (inverse colors). NOVATECH™ DF-500N. You can even grab one here:  http://www.ebay.com/itm/Seimac-DF-500N-Hand-Held-Marine-Direction-Finder-Responds-to-Distress-Beacon-x-/331869664725

I didn't spend a lot of time looking into it, but it appears that Seimac and Novatech and MetOcean are all related companies.

Yes, Seimac and Novatech were adopted siblings.

Cobham Plc acquired Seimac in 2001
Cobham acquired Novatech and Orion Electronics in 2003
Seimac, Orion and Novatech were merged to become Cobham Tracking and Locating in 2007
MetOcean bought Novatech from Cobham in 2010
Cobham got rid of its emergency locator beacon businesses in 2012 (which included Seimac and ACR)
Cobham got rid of its surveillance businesses, including Tracking and Locating, this year
Cobham Plc, a UK company, had sales of over 2 billion English pounds in 2015

MetOcean lists the Novatech DF-500N on its website and states a SAR version is available (click on Read More under technical specs): http://www.metocean.com/products/tracking-monitoring/novatech-beacons-flashers/novatech-beacons/novatech-df-500n

I'm doing testing of a 406 MHz beacon with a proposed intermittent homing signal to see if existing DF units can locate it. RhoTheta/Becker, blue box and cheesblock L-Pers, Mk4 Sniffer, no problems. The Pro-Find not only couldn't find the intermittent beacon, it couldn't find the control beacon with a continuous signal or a standard Pointer 6000 practice beacon. The unit itself might be defective, but given that there are so few of them around, it's not worth trying to figure out if it works or not. It's listed as "No test" instead of pass or fail. As for the Tracker FTV, the only one I can find is a 121.5/243.0 version, so it's also "No test."

Mike

[Luis R. Ramos]

Sardak-

When you give info on models that you tested, can you at least identify if they are hand-helds, and model numbers?

A lot of us are not as experienced as you are, our experience limited only to the L-Pers... and the Tracker...

Earlier I found RhoTheta/Becker, but the only models I could find were aircraft mounts. Are there RhoTheta hand-helds for sale? Model number, please?

Is Blue Box a hand-held df? If so, model number, please... And company...

The M4 Sniffer, can it really be held in the hand as the manual states, or does it need an antenna similar to the old L-Per?

[sardak]

Luis,

Earlier I found RhoTheta/Becker, but the only models I could find were aircraft mounts. Are there RhoTheta hand-helds for sale? Model number, please?

I was referring to the aircraft models. RhoTheta will sell you a manpack version of the RT-500M, if you really want one.
 

Is Blue Box a hand-held df? If so, model number, please... And company...

The blue box is the long-time L-Per with the wooden sticks. The cheesblock is the newer, digital version of the L-Per.

The M4 Sniffer, can it really be held in the hand as the manual states, or does it need an antenna similar to the old L-Per?

The Sniffer needs to be attached to an antenna. Typically, a Yagi is used like this. This picture and more on the Sniffer and antennas at: http://www.rdfantennas.com/index.php


Here is an ACR Vecta 406 prototype for DFing 121.5 and 406 beacons. It has never been put into production. This and the RhoTheta manpack were built in response to a US Coast Guard RFP for a prototype "portable" 406 DF. The projected single unit cost of both, in quantity, was 5 figures left of the decimal.


I found the 2009 GSA price list for the Pro-Find, which started this thread. 
The DF, ear bud and AC/DC charger package was $1,531.49
Adding the 121.775 practice beacon brought the price to $1,675.06
The hard case and spare non-rechargeable C-cell battery pack added $239.29
The ProFIND NT DF/DF 500 N (unit now sold by Novatel) was $1,895.21

Mike

[Check Pilot/Tow Pilot]

The M4 Sniffer, can it really be held in the hand as the manual states, or does it need an antenna similar to the old L-Per?

I love my Mk4 Sniffer and I have used it on many actual missions. I have the split boom antenna from Arrow: http://www.arrowantennas.com/arrowii/121.5-3ii.html and I use three pieces of Velcro antenna to bundle up the pieces. Frankly It takes so long to assemble the antenna that I mostly just use it with a pigtail.  The pigtail antenna from an old airband antenna.

It works great!!

YouTube video of it in operation: https://www.youtube.com/watch?v=s5JSXrffyj0

[Luis R. Ramos]

The antenna instructions state to "keep it to 10 watts if handheld, mounted can be used in 150 watts."

So, how do you adjust that? Is there an outside/internal switch? And why the change? Is operating above 10 watts harmful to the operator?

The Arrow antenna seems to be cheaper...

[SarDragon]

Unless I missed something, the antenna is used receive only, and power ratings are irrelevant.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

[Luis R. Ramos]

Thank you.

Remember, I do not know anything about the Mk 4 Sniffer, and am reacting only on what I see on the website...

[tribalelder]

That legacy l'per on eBay--has likely  been in the case since early 90's?-at least  Practice frequency 121.6 on panel, not stickered for a 121.775 added channel, so not likely it has not been out to play for a long time. It is likely to need new crystal-minimum.

Expect to give the  volume control a blast of tuner cleaner too.

[PHall]

That legacy l'per on eBay--has likely  been in the case since early 90's?-at least  Practice frequency 121.6 on panel, not stickered for a 121.775 added channel, so not likely it has not been out to play for a long time. It is likely to need new crystal-minimum.

Expect to give the  volume control a blast of tuner cleaner too.

Give all of the switches/controls a good blast of tuner cleaner. And clean up any signs of battery corrosion too!

[Eclipse]

That golding handle / antenna combo is the one we're looking at buying.

[Check Pilot/Tow Pilot]

That golding handle / antenna combo is the one we're looking at buying.

Let me know if you want pics.

[Jasonfire7]

So we have 2 of the original L-Per in my squadron. I am looking to upgrade to a better version. I have found everyone's findings about the Pro find to be correct as I have borrowed one and it is junk. The new L-per is sold out and wont return e-mails. I have used the "sniffers" before with great success, And that would be the one I am leaning towards. Has anyone purchased the MK4 sniffer recently? I was attempting to price one out but currently unable to locate any for sale.

[Eclipse]

This is where we'll be getting ours:  http://www.rdfantennas.com/products.php