[HBR] My New HBR-13 Running - Would Like to Ask Questions of HBR Expert

[Whitebear1122]

Hi, I am nearing completion of my HBR-13L project that has been on-going for five years.  I am sitting here listening to 40 meter cw and the “13” is sounding good and signals are extremely stable.  Gosh that Eddystone dial is so smooth.  If it’s drifted, I haven’t perceived it after listening to the same station for 1/2 hour.  Rather than go with Alex Stewart’s HBR-13C center mounted Eddystone design I choose to mount it in the original HBR-16 position on the left so it’s an HBR-13L I guess.  I had read quite a bit about the 13C guys not getting the amplifiers to go into regeneration with the “C” layout.  Ted Crosby wrote about this and was confounded as well.  That was probably my main consideration for keeping the original left side layout.  The 13L certainly does go into regeneration when turned up too high.   I also opted for a 17” wide chassis rather than the smaller 14” because this novice builder would need more room and I needed it too.  

I would like to email with some HBR experts as I have some questions about signal to noise ratio.  I’m hearing plenty of signals but it seems like the background noise is a little higher than I would have expected.  Maybe I don’t know how to adjust the regenerative IF’s and Mixer controls.  I’ve been careful to align properly using a signal generator and an oscilloscope. 

Are you doing additional audio filtering?  I’ve been thinking of trying some passive filtering to try and take the edge off the noise and narrow up the bandwidth.  What sort of bandwidth are you getting?  I’m running Military ARC5’s in the 100 KC IF, and adjusting the coupling doesn’t seem to affect bandwidth.  I have not measured it yet but it’s pretty darn wide.  Maybe I haven’t learned how to adjust them properly.

Everything has been a learning experience here.  Turns out I knew jack squat about superheterodynes until I built one.  Troubleshooting has been a real eye opener in learning what signals look like.  Can’t tell you how long I took to figure out the first mixer and second mixer were working fine.  It was just a jumble of ’scrabble’ on the oscilloscope when I would look at the mixer output.  Once I learned to look at the signals AFTER an initial IF transformer, then things started making a lot of sense.  

The HBR seems nearly as sensitive as my Elecraft KX-3 as measured by using my ear and a signal generator (URM-25), at least on 40 meters.

Tonight I was troubleshooting the S-meter circuit because it didn’t looking like it was working, just displaying a steady reading here and there.  Then I discovered the Lafayette meter is sticking at several places.  Sheesh….. No wonder the circuit looked frozen.  If I move the meter calibration above the sticky areas, it’s working FB :)  A good friend W4MIL gave me a Heathkit meter so maybe it’s time to step up to the Heathkit meter.  I kind of liked the Lafayette look because the bezel was all clear plastic rather than the heavy black bakelite look of the Collins/Heathkit style meter.

Yes I am planning to install knobs soon :)

I have some fresh pictures of the HBR-13 up on my QRZ.COM <http://qrz.com/> page.  

So I’d appreciate hearing from you with some sig/noise and filter advice.  Thanks.  73, Scott WA9WFA