HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 22, 2012, 07:11 PM
Registered User
Joined Aug 2009
19 Posts
Discussion
Corona DSSS Hack Futaba FP-T6NLK AM

There was an old thread here that had a FrSky 2.4 hack of a Fuba FP-T6NLK AM system.

This was my first radio from 1988 so I am kinda nostalgic about it. Even had it gold-stickered back in 1991.

The picture copied below is from the old thread about the FrSky hack on this radio. They mentioned they had problems with jittery servo action using the FrSky internal hack module, and eventually, they modified a FrSky Fuba module to sit on top of the case, and that cleared up any jitter problems. They speculated that the old Fuba's analog IC for PPM output didn't like 2.4g Rf so close and that was the reason they tried an external 2.4g Fuba module strapped on top, which seemed to work.

However, I opted to go with a Corona DSSS hack module, not a FrSky. I connected it exactly as picture indicates, using the three points on the main board that used to connect to the RF board which I removed. I mounted the hack module to the back of the Tx case with double sticky tape, in the lower far right corner just above the charge jack, as far away from the analog IC for PPM as I could get it. So it's not sitting right on top of the IC radiating 2.4g directly over it. And I routed the antenna lead away from the mainboard also as far as I could keep it from the analog IC.

The hack module powers up just fine, and I can put it in bind mode, no problem flashing green/red as normal. When I go to bind the receiver, I can get the two blinks on the Rx LED just fine, indicating that it found the Tx. Then I power down both Tx and Rx. Then power up Rx first, wait 5secs, and power up the Tx sitting at least 6 feet away. However, I get no solid red bind light on the Rx, and no servo response on the stick movement.

I've tried to bind with three different Corona DSSS Rx's, both 8ch and 4ch, and I get the same result. Funny thing is, when I put back the AM Rf board and fire up the old AM Rx, no problems, so I suspect PPM must be working OK.

Any idea why I can't get a bind on the hack set? It's like the Rx handshakes with the Tx OK, but then acts like there is no PPM signal behind it to indicate a bind, and thus, no red light.

Note: unlike the FrSky hack module where the antenna lead comes pre-attached, the Corona DSSS has you solder the antenna lead onto the hack module, which is nice so you can thread it down the radio's original antenna mount like I did. However, is there a trick to soldering the antenna lead? I assume you only want to solder on the center antenna lead to the spot marked ANT, right? It looks like a tiny coax cable with a braided copper outer conducter. I assume you don't connect that braided conducter of the antenna lead to anything on the board, right? (In other words, could the bind problem be antenna related?)

Thanks,

Jon
JonnyW is offline Find More Posts by JonnyW
Last edited by JonnyW; Feb 22, 2012 at 07:17 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 24, 2012, 12:25 AM
Registered User
Joined Aug 2009
19 Posts
Success Converting AM to 2.4G DSSS

Well, the classic Fuba FP-T6NLK AM radio is now officially successfully converted to 2.4G DSSS!

The Corona DSSS hack module is a success. I finally got the Tx and Rx to bind, and it works perfectly, as far as I can tell. There is no hint of servo jitter at all, and the hack module is located inside the Tx case, no need for a case mod at all. The 2.4G antenna is located in the original antenna place and looks great. The bind button and light are conveniently located right on the top right hand side of the Tx case.

I still suspect that the reason for the difficult bind issue is because of an antenna problem. I am not completely certain that I have correctly soldered the antenna lead onto the hack module's ANT joint. The bind became successful when I brought the Tx within 2 feet of the RX. (Most data says the Corona DSS binds best when the Tx and Rx are at least 1meter apart.)

Anyway, the answer is, YES, you can convert an old AM system to 2.4G using a hack module.

My nostalgic first RC radio will fly again!

Jon
JonnyW is offline Find More Posts by JonnyW
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Corona DSSS V2 Hack Thread Gyroguru Radios 460 Nov 27, 2014 12:29 AM
Mini-HowTo Futaba T6X upgrade to 2.4Ghz with the Corona 2.4Ghz DIY Module (DSSS) CT8Z wriggs DIY Electronics 6 Apr 30, 2014 05:48 PM
Help! Corona DSSS hack module problem robonave Radios 14 Oct 04, 2011 12:47 PM
Discussion Suggest from "Corona 2.4Ghz DIY Module & RX dsss" vs "Assan hack" joy4u Radios 5 Jun 15, 2010 12:08 AM
Futaba fp-t6nlk MJnFL Radios 3 Jun 09, 2004 11:21 PM