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Attention: RC-CAM.com will be closing down August 2021.

The RC-Cam.com forum was the very first online community dedicated to the advancement of wireless video cameras on radio controlled (R/C) models. This is now called "FPV" (First Person View). We are proud of the contributions that our members have made to the FPV hobby.

We've seen significant changes over the last twenty years. Initially there were a lot of eager R/C hobbyist that built their own video systems. Allowing these creative individuals to share their work was the purpose of this site. Now the FPV market is flooded with low cost systems; Sadly DiY FPV video projects are now rarely discussed.

RC-CAM.com (main site and forum) will be closing down August 2021. This is being announced now (March 2021) so that everyone has time to download any information that is important to them. After the site is shutdown the information will no longer be available here.

We appreciate every member's involvement with advancing the FPV hobby. It is indeed sad to say goodbye to all our online friends. Be safe and stay healthy.


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Posts posted by jparisse

  1. Thomas... You are like the Shaolin Priest from the old Kung Fu movies! Totally wise but cryptic to your followers! :ph34r:

    I have two sentences setup: GGA and RMC each at 1Hz so the data seems continuous to this human processor. I understand about the pauses but don't understand how one can program the GPS unit to produce them... Should I just lengthen the pause time between the sentences I am currently using (say 2 or 3Hz)? Is it that easy?

    Thanks for teaching me so much. Someday I hope to snatch the pebble from your hand... :D


    Mark... That is VERY cool and about time (ask 'em to make a 1000mW).

  2. The modem is probably perfect but the audio fidelity (antique word) of the 650mW Lawmate TX is not so good...

    I flew a test today with the DZL Modem and above mentioned Lawmate TX. I should point out that I have messed with the audio pot on the TX so much that the screw driver slot is worn down. I think this pot is for impedance matching but on some TXs (as Mr. RC-CAM points out) is a carrier frequency adjustment for the audio channel. In either way, I used it to maximize the performance with a TinyTrac3 and, later, with the DZL Modem (less so). The “non-factory” setting of this pot may skew my results as reported herein. Also, I flew at a soccer field the Port of Los Angeles at Long Beach (one of the busiest sea ports in the World in one of the largest cities in the US) so R.F. traffic was very dense.

    I created a 5-mile GPS route for the plane to follow and used a laptop with cached Google Earth data for moving map visualization. The route was plotted over a 15 acre field with the plane staying within 1000' (305m) of the RX. The route took 20 minutes to fly and I had one loooong (5 minute) data drop out that wouldn't reset even with a power cycle of the DZL RX. The lights on my serial port adapter (my only TTL diagnostic tool at the field) blinked away and I restarted GE+ with no positive effect. The data stream restarted, by itself, a few minutes before I landed.

    I plan on switching over to the Airwave products to see if I get better performance ( like Thomas B) ) so wish me luck. BTW are there any commercial products build around the Airwave modules that Intelligent Flight AU sells? They seem to work well, are well supported on this forum and priced right (thanks Mark) but I am curious about a factory built and tested unit...


  3. Testing with Airwave

    I finished assembling a 633 TX and 634 RX from Airwave and tested the DZL Modem with them.

    Video looked clear and very much like the Lawmate product. The difference (as Thomas has already pointed out) is in the quality of the audio link(s). The square wave looked almost identical to Thomas’ screen shots and the TX tolerated a much wider range of pot settings. I added a .01uf, .1uf and 1uf filter cap just to see/hear if I could detect any difference or benefit. Maybe in a harsher airborne RF environment a filter cap could ground out LF but on the bench, I couldn’t see how it helps.


  4. Actually Gil, we are only interested in the set-up into which you have installed the DZL modem. This thread is for DZL users who wish to share information on the DZL modem and how it integrated into their plane. I bet most folks on RC-CAM have planes with cameras in 'em. :rolleyes:

    I must reason that the DZL Modem works perfectly for you without any modifications.

    Great... so far 100% success.


  5. Just to put some numbers to it... at 5.5V the NTE1904 rose to 108.5F (42.5C) in three minutes. I didn't push it past that. That should be OK with a heatsink and perhaps outside of the fuselage.

    I was hoping to design a PCB without a heatsink and keep it exposed to air (relying on the AWM633 to self cool). :rolleyes: If I mount the VReg upside-down, it can be folded over and attached to a piece of brass or aluminum that is laid across the top of the AWM633. Sort of like a heatsink sandwich (heatsink, component space, PCB).

    The heatsink only adds the option to use 5.5V rather than a single LiPoly cell. So perhaps IT should be an option. Just thinking...


  6. I'm attempting to power the Airwave 633 TXs at 3.3V and RFI on switchers bugs me too. So I'm thinking of using a LDO linear regulator on a low input voltage instead.

    As a test, I dropped a 640mA load across a NTE1904 3.3V Linear LDO Regulator and powered it with a single cell LiPoly (4.2V fully charged). The NTE1904 was mounted vertically (stuck in a breadboard) without a heatsink. I took temperature measurements at 5-minute intervals with a Fluke 61 IR Thermometer at 2". Room temperature was 70F and the air was static. After 10 minutes the chip leveled off at 81.5F (11.5F over ambient) and stayed there for the 20-minute duration of the test.

    Given the informal testing I did at input voltages of 8.4V and 5.5V, I believe that a linear regulator may run too hot unless in constantly moving air. It may be an option worth considering at an input voltage of 4.2V if one, like me, doesn’t like introducing the potential for RF interference with a (albeit more efficient) switching power supply.

    Before I finalize my AWM633 PCB design, I’d like to know if anybody here is powering their AWM633TX with a linear regulator?


  7. Gil,

    Can you share your setup details for the good of the group? Did you use a filter cap on the receiver? What component values did you use? What brand of Video TX/RX are you using?

    I just finished installing the last of the Beta modems into my UAV and ground testing. I'm not using a filter cap in the RX and I'm using the standard component values of the kit. I have a Black Widow AV setup (Lawmate) with a 600mW 2.4GHz TX and a simple standard RX (I'll use my high gain diversity system when I flight test).

    The video is clear and the telemetry seems rock solid. When the morning fog condition lifts, I'll be able to do some testing in the air. My long range ground testing of a couple weeks ago tells me I should have no problem in the air.

    I'm taking a photo of the finished RX so I can annotate it with Photoshop to help the kit builders. Good luck guys and yes, BIG THANKS to DZL and Thomas for the brainpower.



  8. Thomas wrote: "the square wave from the DZL encoder must be filtered right"...

    This part has me a little :blink: ... What is the goal of the filter cap? Is it to reduce low frequency noise (high-pass) or to shape the square wave to a triangle (integrator)?

    My setup had the best results without any filter cap at all. I reason that whatever circuitry on the receiving end of my Video Transmitter is shaping the square wave to resemble the scope traces I uploaded to the DZL thread. All I had to do on the DZL TX side was adjust my output level to get it to work (100k pot to ground, wiper out).

    I made pads/holes on the Beta DZL kits so folks could experiment with a filter cap and I included a .1uf cap to get them started.


  9. OK Guys, the first batch of Beta DZL Modems has shipped to Hartwig, Wavess and qnzkrew via airmail. International postage cost $6.33 and domestic was less than $2.00. So, the new shipping terms will be $7.00 International and $2.00 U.S..

    The TX has standard .1” pin headers for Power and GPS in. One can use a JST, servo or other connector that has.1” pin spacing. The output is a shielded cable terminated with an RCA phono plug. There is a jumper to select inverted or non-inverted output and I’ve left a space for a filter cap should one determine if a filter cap is necessary (one of the primary objectives of the Beta program is to compare interface issues with the TX and our various brands/models of video transmitters).

    Also included in the kits are a 1N4004 diode and .1uf capacitor to add to the RX per Thomas’ suggestions a few posts ago as well as a .1uf filter cap with which to experiment (my unit works fine without one).

    There are three more kits available on a first come basis. $45 w/o case, $55 w/case and $80 assembled. Send a payment via Paypal to jparisse[AT]teslacoil.com after checking this thread first (I will post here when the three units are gone).

    Much thank to Hartwig and Wavess for overpaying on shipping. I spent the extra money at Starbucks… ;-) qnzkrew gets a partial refund (after coffee of course)!



  10. Mark wrote: "Postage should be no more than $5 to Australia via USPS airmail btw"

    I used the USPS postage rate finder on the web and I couldn't get the price below $17 to Perth so I'm shipping at a loss*. Can you send a link on how to find a better rate?

    To All,

    Yes, once the Beta testers have confirmed their orders, either Mark Harris or I (or perhaps both) will offer the kit for sale to the general public. The consumer price will be slightly higher than the Beta Testing price but the kit form will help make this affordable to everyone. If any Beta tested back out, I will offer remaining beta kits on a first come, first served basis.


    · I'm taking a loss on the entire Beta project but this is a labor of passion because I believe that every AP flyer should incorporate moving map software for utility, safety and aircraft recovery. This is a hobby project for me and I want to share with my peers.

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