Page 1 of 1
Common IF Board for 76, 122 and 241GHz
Posted: Tue Feb 15, 2011 4:14 pm
by VK2GG
Hi all,
Philipp DL2AM sells a stand-alone aluminium enclosure for the Kuhne 47GHz IF pcb.
(They actually come from Hubert Krause of Micro-Mechanik).
Makes it possible to connect/dis-connect to mixer for 76 or 122 or 241.
Now to find someone to glue my mixer diodes to the mixer pcb...
Dan VK2GG
Re: Common IF Board for 76, 122 and 241GHz
Posted: Sat Apr 09, 2011 7:24 pm
by VK2GG
I have just completed 2 X IF boards more-or-less as per Philipp's photo.
It even works, thanks to the stand-alone design, it can be tested using a weak 144mhz signal and a power meter.
One surprise was the configuration of the PTT relay; I must confess to not having studied the circuit diagram very closely, and it turns out that the relay is ACTIVATED in Rx mode! Philipp's blue wire to the neg of the relay which I had originally thought to be a manual PTT, happens to be an earth on Rx indicator - useful for a Tx/Rx LED, or to switch +5..+6 to the multiplier for Tx/Rx respectively.
(see attached circuit). ( CURRENTLY HAVING DIFFICULTY UPLOADING PIC'S)
I have also attached a photo of the parts placement diagram as per DB6NT.
Parts were obtained as follows:
- Aluminium case - Herbert Krause (Micro-Mechanic) or via DL2AM
- PCB - Kuhne
- 12v relay - Element-14 or Altronics for an equivalent
- BFP81 lo noise NPN IF amp - China Chip
- All other components - Altronics/Jaycar
(Come on guys!!)
Dan