500 Khz signal generated

The 500 KHz transmission path works. I mixed the LO signal with a 4,433 MHz signal out of a simple xtal oscillator. The mixed signal is filtered by 2 455 KHz  IF filters. It was easy to tune those to 500 KHz.
So the transmission path works for CW. I also improved stability of the LO.
Next step is to make a IF amplifier for the receiver.

Quicky for 500 KHz

I am building a small 500 KHz transceiver. It will be simple using stuff from the Junkbox. I expect that it can be build quickly.

It will be a simple super with 4.433 KHz As IF. The  local oscillator will be 500 KHz lower. I found 2 xtals that can be used to generate signals  3.93 KHz  apart. A NE602 Mixer will be used to mix those signals. The wanted 3.93 MHz signal can be filtered out using a bandfilter.

The IF strip will be based on the bitx 20 concept. I will use a Mc1350p as  IF amplifier. Building AGC is not difficult using this amplifier.  It will be suitable for SSB so I can use WSPR.

Current status:
Xtal oscillators and mixer are ready. Some fine tuning needs tor be done though.  

 

4 Meter in the Netherlands

Today I read on the VERON side that we may get access to 4 meter. 70 to 70.5 MHz to be precise.

That would be great. I am thinking about building something for that band. I could use a transverter and my 50 MHz transceiver. I could use the concept of my CB to ham transverter. The xtal frequency can be a fixed, no need to make it tunable.  alternatively I could make a transverter for a CB radio.

Design idea 1: Use 50 MHz transceiver. Make a xtal oscillator at 20 MHz. Xtal for frequency is standard. Mix with 50 MHz using a SBL-1 mixer. Some filtering is needed at the input. I am sure a preamplifier is needed as well. This makes a basic transverter. Then the output power must be boosted to 8 watt PEP. A power module can take care of that. I found a few on Ebay.

Design Idea 2: Use CB radio and a transverter. It looks like design idea 1. However the Xtal frequency is 43 MHz and it should be tunable over 20 KHz.  This 43 MHz is not available as  standard Xtal so I may have to mix 2 Xtal signals to get to 43 MHz. Maybe 25 MHz and 18 MHz.

cb collection

Here some pictures of my collection of CB radio's.  Most of them  are working.
Some of them will be modified for use on Ham bands. Some others will be stripped for parts.

9 MHz IF strip

I am working on a IF strip for a new homebrew HF transceiver.
Some of the design goals:
-SSB/CW
-Variable IF filter width.
-Noise blanker
-AGC fast and slow.
I am building in a tin box. The components are mounted on the tin bottom of the box.
Currently the IF filters an the IF amplifier for RX are working. A picture will be posted soon.

The new HF transceiver will be described in a new blog dedicated to the project.