2m (144MHz) Transverter by YO5PBG

This transverter was created by me (YO5PBG) just before moving to Bucharest (for more than 3 years) and cancelling all my HAM "operations", in november 2004. It was hardly-designed to achieve good performance, solid state and easy to use equipement. I'm curentlly using this with a modified (for transverter operations) President Lincoln CB / Amateur Radio, all mode transceiver (26-30 MHz in 100Hz steps).

Features:

• stable RF design
• electronic voltage switching and automated via the single RF cable connecting the transverter to the transceiver (needs 8 to 12 Volts DC from the transceiver, suplied via a RF choke to the RF path)
• low noise on receive
• transmitting power 5 to 7 watts, excellent for local or portable DX operating
• adjustable TX output power
• best used with an separate low noise RX amplifier for DX-ing, eventually mounted directly on your antenna

(click to enlarge this image)

Content Management System bug encountered

UPDATE jan. 14: All lost data was manually republished.

Today, trying to update this website, i encountered a big technical bug, regarding the platform on which Sinaptic.ro is running. 

Now I must "redo" somehow some lost work. Last database backup was made on 15 december 2008.

Sorry,

Adrian

QRP? You are joking!

I never used QRO, i mean more than 10 watts. Oh no, i did. I did it, but without any satisfaction. I used 100W to 2KW and hi-gain antennas from the local radioclub (YO5KAD), but only when I was borred and wanted to make a QSO on HF from the club. And I worked only some european stations, yes some DX's also, seen active on the cluster.

But the ultimate satisfaction is to make a lot of QSO's, with ham's all over the world, with only 5 watts, using a stupid dipole - when others using Yagi's and 100W+ have to wait more than you to work the same stations. Tell me that i'm

AF Beep tone for your Transceiver

Sometimes is good to signal the end of your transmision, not by words, but rapidly with the help of a beep. I once used a "K" tone generator for this, but when I encountered those ultrafast QSO's in 6m Sporadic E or F2 Propagation, i wanted something like a "fraction" of second beep type.

So I designed this one-IC  circuit. It uses a CD4093 trigger Smith CMOS, and is integrated into the microphone case. I used a dynamic mike @ 600 Ohms, but you may use also a little condenser (electret) type. Zener diode could be change with another voltage type, up to 9V, changing also some values (starred in this schematic). CD4093 IC had Vdd or "+" at pin 14 and  Vss or "-" at pin 7 (supply pins).

YO5PBG first 6m FM Transceiver

This transceiver was conceived years ago, when I was 19 years old. It was intended for a local and quite private network (just me and another HAM had 6m equipement in this part of Romania in 2002) between me and a friend who was new in amateur radio. This transceiver has just one channel, but you may transform the Local Oscillator into a VFX, VFO or VXO. It is easy because one LO is used both for receiving and transmiting. As you can see, we have no mechanical relays and no hard to find or not replaceable parts.

Receiver

A MOSFET transistor amplifies the 50 MHz signal, filtered by a common RX/TX 6m filter composed by a two pole LC circuit. The diode double balanced mixer is also a common part for receiving andtransmitting. LO signal is made from a simple single transistor crystal oscillator of 50,XXX MHz desired frequency minus IF (for example, i used the second overtone of a 20.000MHz crystal that gives 40.000MHz LO frequency - combined with 10.7MHz IF gives 50,7MHz RX/TX frequency). Mixed signal is amplified by a bipolar transistor and filtered by a ceramic type 10,7MHz filter, than sent to the FM IF receiver integrated circuit MC3357 from Motorola. Resulting AF, demotulated signal, is amplified by a reliable and simple LM386 IC.

(Click to enlarge RF Unit)

I'm going slightly mad

It's not just a global monetary-system crisis. It's also my crisis. I would like to sleep, only. To dream, only.

That's why I cannot concentrate on any project very well right now. This year was a big challenge in my life, but i realize that this year was a "stabilisation" one. I'm as always very frustrated of the very low level actual state of humans, but surprising or not, I'm more relaxed than ever. It's not good, I know, but I cannot permit myself any stress, because I discovered that my health is more important than anything else.

S902 Transceiver RF & PA Block Diagrams

I just finished the "digital style" design of the most of the block digram units for the planned S902 All mode Multiband Transceiver. The next step is to show you the IF-AF and LO Units Block Diagrams, of course a.s.a.p.

Click this image to enlarge.

S902 Transceiver Basic Block Diagram

For those interested in my All Mode / All Band Transceiver Project, this is the basic block diagram. Description and roadmap for S902 (code name) Transceiver is available here. Intermediary frequency for 2m, HF and 70 cm is 50-60 MHz (also used for 6m band).

Number of units could be larger, until the project will be finished. For example LPF (Low Pass Filters) for HF Output is not shown here. Also, the antenna switching system for 70 cm is possible to be based on PIN diodes and helix or "PI" LPF's on a separate PCB.

I will soon publish separate block diagrams for each unit.

These days I had two busy hands

Two cases of polish 300MHz old industrial (Unitra/Radmor) transceivers available. Two hands. Of my own. I decided that this two cases coupled somehow could be a single one. The one for my planned "all mode / all band" transceiver for 2009. So... i have cut some quality alluminum whith my own hands and minimum mechanical equipement, I... And finally, I made the case! It has about 240x240x130 mm (L x l x h). "Making of" the case is available in the gallery menu. I also made some tests on a 70cm PA and transverter, but this is subject for another post.

Sinaptic.ro is changing the hosting server

UPDATE: Migration was completed today, 26 nov. 2008.

From about two weeks Sinaptic.ro is experiencing some server problems so, I will move the site and DNS to another server at the hosting company request. This operation is shedulled for today, but the complete migration could take longer than a day.

So please accept my apologies, but this situation is independent of my will.

Thank You,

Adrian - YO5PBG