Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[DocMartin]

Time spent today looking over the new acquisition of an old "Franken-hacked" Robbe F-14 radio, once used by a submarine enthusiast.  I say "Franken-hacked" because it has several interesting modifications. 

First, the main circuit board has been previously sliced to separate the channel functions (8 channel) from the transmit circuit (originally ? 40 MHz or 35 MHz transmit board).  This cut circuit board has been married to a 75 MHz transmit board via 4 wire jumpers, respectively.  The has "0019" printed on the channel side that I assume is the manufacture date of May 2000 (19th week of 2000).
 
Second, the channels 3 & 4 joystick has been modified to a "twin-stick" configuration, similar in function to the F-14 Navy twin stick module, without the look of the twin stick (a completely hand-made job). 

Finally, a Robbe T964 module has been installed, occupying channels 7 & 8.  The module has two proportional switches (potentiometers), a two-position switch, and power supply via a plug that connects to the TRAINER port.  The module has T964 printed on the circuit board.  The board is clearly a Robbe module, as I own many of the F-14 add-on modules (which are marked similarly).


The radio did NOT come with any printed instructions.  My search of the internet has yielded only two photographs of a similar module for sale in Germany (see attached).  No further information can be garnered from the listing.  My impression is that this is some type of early mixing module.

Can anyone provide any information regarding this module and/or its function??

 

[DocMartin]

A picture is worth a thousand words.  Added below are pics showing the "FrankenHacked" board, the "Twin-stick" mod, and the T964 module, in situ.

[HMS Invisible]

I remember this on-board mixer available for the F14 & F16. I have a 7channel version of the F14 and a copy of the Futaba catalogue from this era.
The catalogue will only furnish pictures of the extensive range of accessories with ordering codes but no instructions.

Here is a reference and I see one for sale in an Austrian sales message board.
I'm sure the pots are just gain control presets to alter the mix ratio. That will be the key detail that the poster missed. You can figure the rest out without instructions.

A trainer port for these radios was another add-on.
The F14 printed circuit layout lends itself to sawing off the r.f. board .
Yes, you are correct if you're thinking "but it's a Tx mixer, not an on-board mixer"

[DocMartin]

HMS I:
Thank you for the link.  Knowing the way Robbe provided instructions with the F-14 radio (limited), it may take a while to find useful information.  The best hope is to find the model number or name of the module.  The printed T964 hasn't helped much, yet.

This previous owner was quite talented in an era before 3D printing.

I have discovered that the gimbal was from an old Futaba 2 channel Attack-SR radio.  This makes sense given the intertwined relationship between Robbe and Futaba.

In regards to the FrankenHacked circuit board,  I find this most interesting.   My first Robbe transmitter purchased was an F-14 Navy, which here is the US sold in limited numbers (early 2000s).  It sat on a shelf for years as I slowly collected the accessory modules I wanted.  By the time I amassed the expensive and necessary modules, I discovered that the transmitter was defective.  None of the attached modules worked when connected.  Frustrated and angry at my purchase (caveat emptor), I shelved the radio.  Fast forward to my recent purchase, I have tested the old modules and found that they work just fine.  This leads me to believe that the channel side of the circuit board (which has the Futaba IC chip attached) is faulty.

Seeing this modified board has put me in search of any old Robbe F-14 regardless of transmit frequency (35MHz, 40MHz, etc).  I may now be able to resurrect my foolish purchase from years ago.

[John W E]

hi there


There is a guy who I was dealing with via Ebay - he seems to deal with 'old' radio sets such as Futaba, Graupner etc


here is a link [size=78%]micha0007 | eBay Stores[/size]   He helped me out with a new circuit board for the Graupner transmitter which I eventually did a conversion over to 2.4 and the circuit board which I used looks remarkably similar to the one that you have put a photograph of on here.  He may be able to help you out with spares (although he may be a bit pricey - it was worth it for me).


John

[HMS Invisible]

 

HMS I:
Thank you for the link.  Knowing the way Robbe provided instructions with the F-14 radio (limited), it may take a wh...

Seeing this modified board has put me in search of any old Robbe F-14 regardless of transmit frequency (35MHz, 40MHz, etc).  I may now be able to resurrect my foolish purchase from years ago.

The facebook group diveintomodelsubmarines had no shortage of native German speakers who also speak English. I don't do Facebook  but recall Herr Engel popped in with Engel doc help & there were many members competent in radio servicing when it was open-to-public and moderated by the group founder.
 I could only assist with diagnostics on the earlier NE5044 based 7-channel set if you were probing with a meter or scope. (I could still do with a 3-way adapter, T.G.  )
 A Futaba catalogue came with my F14 and I think other people will have kept these brochures. If I find one of my copies I will photo-scan whatever is relevant.
 I don't know if my guess of the Tx mixer was fully understood. It will be a simple V-tail Tx mixer as found where you once had panel mounted screwdriver/fingernail rotary presets. The Futaba F14/F16 way of powering them is by daisy-chaining the white connectors which start on the encoder board.

[Treble]

DocMartin , I believe I have an F14 transmitter SOMEWHERE . It's a while since I've seen it , but I'll try and dig it out if you're still interested , though it may take a while due to other commitments. I am in the UK .

[DocMartin]

Treble:
Interested as long as it's an 8 channel transmitter.  Keep me in mind.  I fully understand the "other commitments" side of life.  I am there too!     Thx!