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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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Everything posted by jparisse

  1. DZL Modem Beta Kit Options Six Kits Available – Beta Testers first then others… The DZL Modem is a pair of small electronic circuits that allows a small aircraft, equipped with GPS to easily send 4800-baud GPS serial data to a ground station using the audio channel of common video transmitters. A small modulator (DZLTX1) takes TTL level GPS serial data and converts it to an audio tone that is transmitted over the audio channel of one’s video transmitter. The ground-based demodulator (DZLRX1) connects to the audio output of a video receiver and provides serial output that can be used to dr
  2. Mark, At work (www.teslacoil.com), I make my electrical connections with a 3/4" box wrench. The only soldering iron at work is a 120W Weller with a 1/2" wide tip. Low voltage for us is around 600V. Our ammeters are all "clamp-on". I live in a world where a 20A fuse might as well be jewelry like a shiny little earring. My 45 year old eyes NEED the magnifying glass. The RX board is 1.75" x 2" and it's size was dictated by the Serpac A-20 enclosure (it was nice to have all that room) and the fact that it is not an airborne component. The TX measures .625" x 1.25" and is the same size as o
  3. Thomas, Thanks for the review... I wondered about the input side capacitor of U3 as the datasheet indicated it is optional and only needed for long runs to the power supply (or wording to that effect). I was planning on adding a discrete cap to the parts list so beta testers could experiment with it. I should have taken the "safe not sorry" approach and included it anyway. The output side has a 100uf, 50V electrolytic. The input diode is a nice touch (you're a nicer guy than me... I was gonna let it burn as a lesson to the user). Just kidding... ! That should be an easy fix to the
  4. DZL Beta Testers 0 Jeff Parisse - Paid 0 qnzkrew - Paid 0 DZL 1 Mark Harris 2 Gary Mortimer 3 Jorge (Wavess) - Paid 4 Hartwig - Paid 5 Sébastien Gravit (tazdevil3000) Guys, Please PM me the address that you would like your DZL Modem kit to be sent. Since this is such an international group (Scott lives two miles from me... the rest of you are all over the globe!) it will give me a chance to budget postage. I understand that you don't know the cost yet but it will be the same as mine (less really ) and if, after knowing the cost, you choose to opt out, no problem at all as th
  5. OH MY GOD!!! DZL !!! The man who has caused all this mess!!! Welcome! It is an honor to meet you sir. Great job on that modem dude!... It has been in my dreams and hands for weeks as I ready your device for public consumption. I have parts for six kits (mine plus the 5 beta units) however, I have eight prototype PCBs (no silkscreen) on order so I can set aside another for you. Once the prototype is beta tested, I have chips and discrete parts to make an order of 20 for Mark Harris should he want them. I'm waiting on ordering the A-20 enclosures because I will probably silks
  6. Hi Guys... The DZLRX01 boards are on the way. Beta testers get first batch... Jeff
  7. I was thinking of the MAX233 for size reasons given that every ounce and inch (gram and millimeter) count in airborne applications. Perhaps make the TTL version with a header for an optional TTL to Serial "daughtercard"? I used the less expensive and capacitor laden chip for the RX since it is used on the ground and the PCB size is dictated by the mounting holes of the enclosure. Jeff So far the following three people have signed up for the five available beta units (the cost will be my cost - TBD as soon as I know - it ain't much.. 0 Jeff Parisse 00 Scott Foes 1 Mark H
  8. Progress Report - DZL Modem RX The five prototype DZLRX1 kits are almost ready. Shown below is the handmade PCB and the Serpac A-20 box I've chosen for the receiver unit. There is no amplifier stage at this point and I'd like to leave it that way unless beta testing points otherwise. I will prototype the DZLTX1 (TTL TX) tomorrow. I know "WE" don't need a RS-232 version since "WE" can solder that up without delay. The general AP marketplace, however, may NEED a RS-232 GPS input option so the present TX design includes a MAX233 (no capacitors although 6x more expensive than a MAX232 and ca
  9. Question to Thomas (et. al.), You wrote: "ok I know this is a crasy test with out any filter at all on the tx side." Is a filter on the DZL TX necessary?... Can we assume a filter on the input side of whatever device (audio channel of a VidTX) to which the DZL TX may be connected? I have found that the filter (of various values) works against me in my trials. My lack knowledge and experience in this area works against me too but that's another story. The DZL RX seems to be immune to an amazing amount of crud (now that I have it working). Jeff
  10. I continue to work on the DZL Modem commercial prototype. The first TX board will be TTL only as it's the smallest and easiest to make. The RX is going to be built into a small SerPac box to allow it to survive plugging and unplugging of the DB9 and RCA connectors. The battery compartment option is only available on the larger box (A-21) and it will force all connections to be made on the front panel. So.... I'm axing the battery in favor of a DC IN jack (6-13v) and using a smaller box (A-20). Printing on the box top (labels, logos, ext.) will add a $150 set-up fee and $1.60 per box fee so I'm
  11. Output Stage Test Report I just got finished with a couple of days of testing various TX output stages to work with my TX (Lawmate 600mW from BW) and a simple gain pot alone seems to work best with what I’m using. Once the 633s get here, I test with those too. The output into the radio link TX is pretty square and becomes pretty round by the time it is output from the radio link RX (no surprise). Lowering the gain made a big difference in “receive ability” whereas the filter properties (resistor/cap values) did not seem to affect “receive ability” as much. I have a flight scheduled for
  12. OK Guys... I'm getting ready to purchase a bunch of chips and components for the DZL Modem kit. Since the HEX is in public domain, I'm thinking of offering two versions; parts only and fully assembled. That way we (I say "we" because each sale will generate a 2% payment to DZL as per request earlier in this thread) can provide product to the hobbyist and non-hobbyist. I have a local company willing to beta test what I produce (they download IMU data from a small UAV and this modem will help lower their on-board complexity) and I will set up a web site to act a central point of contact fo
  13. Mark, Now that you mention it, I can see Thomas reflected in his screenshot! You guys are some low tech high teckkies!!! Given my (ultra simple) modem problem, I'm starting to think I ENJOY banging my head against a wall.... Jeff
  14. Thomas, I was overdriving the input side of the modem with RS-232 levels. Once I added a MAX232 and later switched to a TTL level EM-411 the modem works great. I've been building and testing Eladio Martinez's RCAP v3 and AltHold over at RCGroups so I've been off the modem project. Next week, I'll move back over and match the modem to my Lawmate TX/RX and give it a go. I'm ordering some Airwave modules so I can get on the same page as you guys and get this thing working on the air! Mark, I bet that pot is an audio impedance matching pot. That's what it is on the Lawmate RXs. Mine is
  15. Mark, On the RX side, does one NEED the data channel of the 636?... Does the TX have to have a data channel too?... Basically I want 500mW of transmitting power and if I could work with my Diversity receiver, that'd be great. I looked up the frequencies of the channels I'm using and they are 2.410, 2.430, 2.450, 2.47Ghz - although there is a selector for eight channels. I will be using one audio channel for data. I'm working on DZL's and Thomas S's modem project but if I can't get that to work over range, I will revert back to APRS and a TinyTrack3. Thanks for your help.
  16. I’m using the 2.4GHz, 600mW video transmitter / receiver from Black Widow AV. I believe that these TX/RXs are made by LawMate in Taiwan. I’m going to get the DZL Modem to work over my radio link this weekend. I’ll report back here if I have any success. I’ll look into how I can grab screens from my scope too. I attempted to find a link to Airwave 633 and didn’t… Got a link to those RF modules?… Jeff
  17. I'm Back!!!! While troubleshooting another project, I found out that the modem I was using was RS-232! So, I placed a MAX232 on it and THEN plugged it into DZL's modem and WALA!!!! The thing works GREAT over a wire but I still have to impediance match it to work with my TX/RX. The giveaway was the TRIANGLE waves I was seeing.... they are supposed to be square. Anyway... I'll be working on the analog stage to get it to work over my radio. Jeff Thomas... nice work on the OSD flying wing!!!
  18. I usually succeed at the things I set out to do. Not always, but usually. This was a great exercise because; 1. it rekindled my electronics hobby (at least at the discrete part level), 2. I learned a thing or two about AVR microprocessors and I have a couple of leftover ATTINT2313s with which to play and 3. I found that it is easy to underestimate the difficulty of this particular task. I talked this project over with some friends in the aerospace industry here in El Segundo. I seems generally accepted that cramming 4800 baud down a 10kHz pipe requires a more robust encoding and error corre
  19. I works over a wire... some of the time. Over a RF link?... I don't think so. I've hit the time/money wall. I give up. I'll be gettin' a Maxstream. Jeff
  20. Changing R3 in the TX to a pot (to boost gain) worked to produce resonable looking digital on the RX out. It is inverted (and changing phase on TX does not change phase on RX) so I will invert with HW to a "proper" signal. Not seeing the source code, I'm not sure if the signal can be inverted in SW. Anybody still with me on this one?... Jeff
  21. Progress So far, still no luck. I'm getting digital out but it is not the same as digital in. I switched to external crystal oscillators to rule out clock problems. Next, I'll build in a pot to the output side of the TX and input side of the RX to adjust/match gains. Jeff
  22. Progress so far: I separated the project onto two protoboards. I am getting a digital out signal from the RX but it doesn’t resemble the GPS serial data going into the TX. Hooking up a MAX232 seems to clean up the signal but not enough for me, the terminal program or Google Earth Plus to recognize it as a GPS serial. The pulses are very wide. Observations: 1. I get an error in the message window of AVRStudio 4 that I don’t have the WinAVR tools installed: “gcc plug-in: No WinAVR installation found. The AVR GCC plug-in can still be used if you set up your own build tools.” So far, I ha
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