Neat project. There are a number of Peak reading board designs out there at extremely low prices already, including the factory board without most of those features if one is a Bird "purist".
http://www.nm3e.com/images/4300-405-B-11-26-13.jpgOne of my 43s has that board installed. It really does meet all of my needs in that meter. It's rare that I can't AM, FM or CW modulate my transmitters under test anyway. The peak module is almost little more than a novelty for operating other modes and modulation types.
I've never found the need to temperature compensate readings from the meter for real world applications. Bench work that needs that level of accuracy is done with an RF service monitor that has been "semi-recently" calibrated (it's a hobby, not my livelihood) and sanity checked from time to time.
I appreciate your enthusiasm and interest in making a board like this though. Are you planning it as a commercial venture or just an open hardware project to share? (Either is fine with me, I'm not an arguer for how others should spend their bench time.)
I just want to be honest about my hobby use pattern for you, so you have one man's (perhaps useless) opinion. (You decide.)
If my Bird that has the factory peak reading board in it didn't come with it installed when I purchased it, I wouldn't go out of my way to add it.
Just my two cents. In fact, my main concern about that board is making sure to remove and replace the batteries once in a while so they don't leak and destroy things. I could see modifying that Bird with an external power jack and adding a proper way to feed it power from outside the meter, just as you're suggesting in your design as a design fix. Or in my case, simply removing the batteries and only installing them when needed.
Logging, I doubt I would need. Many locations I need to use the Bird I would never leave it there unattended, much less with a laptop attached to it. For my use pattern it's either a field device for testing someone else's gear or club gear, or it's in my shack on the bench available for a quick test of something without warming up the service monitor.
I haven't run across a need to log RF output of a transmitter over any length of time I couldn't just stare at the meter for, yet. Not saying I'll never run into an intermittent transmitter but most of the radios I work on aren't rated for 100% duty cycle anyway barring a few commercial grade FM radios and amps. So leaving them in continuous transmit or looking for an intermittent isn't likely.
I have only seen one transmitter be intermittent enough to warrant pulling it off a mountaintop site for further bench investigation once in 26 years of playing with radios... and it was pretty obvious what it was doing once it was on the bench. It had been hit by lightning and the circuit board under the connection from the output of a 100W RF amplifier to the final low pass filter board had been turned into conductive charcoal. It was intermittently arcing over through the burnt board to chassis ground. A new LPF board from a dead donor PA, and some careful repairs of the edge of the power amplifier board and it was back in action, but was still never sent anywhere to a remote location where it would be hard to reach and service in winter, ever again. It got used as the PA on a link radio at a club member's house where a phone call could get it powered off if it ever went screwy or dirty on air.
Tunable time constant is a nice trick, but not sure I need it.
Dial lighting would be "nice to have" but usually once this thing is wired inline inside a crowded cabinet or attached to essentially immovable hardline, it's not going anywhere and a flashlight suffices -- if we haven't set up bright worklights in the cabinet of gear during a larger project or PA or exciter replacement on site. On the workbench it's not going to be used.
Slug range extension... I have a full Bird case full of slugs of all sorts and power levels. This was helped by keeping a few oddballs that I didn't have from my dad's Bird slug collection when he passed on. But I see the appeal for someone who doesn't have a reasonable collection of slugs.
So there's my brain dump for you. I still very much like your idea and hope if you decide to pursue it that you can share the project story with us. I always like reading about a good project and any challenges someone faced during design and test and any iterations.
All the best... DE WY0X.
Home
Help
Search
Login
Register
