01-30-2014, 08:26 AM
Re: an AM transmitter. I actually use my HP3325A function generator as an AM transmitter if I need one. This is another reason I like to use it for my signal generator. With the A version you need a 2nd audio signal generator also.
The HP3325B (later version) actually has an internal modulation source also so you don't need the 2nd audio osc.
Before anyone spends very much on a dedicated AM transmitter you should look at getting a used 3325A or B instead. They are great for doing alignments and as a general purpose function generator. Can't beat
the totally accurate frequencies you get and complete accurate amplitude control
Re: Minimal experience with vintage tube electronics and lots of modern electronics experience. I was like that also to some degree but always grew up with tube stuff in my teen years so always had some knowledge of the older stuff. My knowledge has increased 100x in recent years as I work on these old radios.
Best advice is to be careful of the high voltages, get yourself a variac and a way of putting a light bulb in series with the line cord when you first do a power up.
Always replace old capacitors no matter what. Electrolytics and paper caps. Micas are probably good although not always.
You are taking a huge risk by leaving in old caps. If the wrong one shorts out then you can take out transformers or coils or who knows what and then you may or may not be able to fix it again.
The HP3325B (later version) actually has an internal modulation source also so you don't need the 2nd audio osc.
Before anyone spends very much on a dedicated AM transmitter you should look at getting a used 3325A or B instead. They are great for doing alignments and as a general purpose function generator. Can't beat
the totally accurate frequencies you get and complete accurate amplitude control
Re: Minimal experience with vintage tube electronics and lots of modern electronics experience. I was like that also to some degree but always grew up with tube stuff in my teen years so always had some knowledge of the older stuff. My knowledge has increased 100x in recent years as I work on these old radios.
Best advice is to be careful of the high voltages, get yourself a variac and a way of putting a light bulb in series with the line cord when you first do a power up.
Always replace old capacitors no matter what. Electrolytics and paper caps. Micas are probably good although not always.
You are taking a huge risk by leaving in old caps. If the wrong one shorts out then you can take out transformers or coils or who knows what and then you may or may not be able to fix it again.
