[Heath] HW-16 update and additional question (11 MAR 14)

Mark Johnson mvjohn at sympatico.ca
Tue Mar 11 12:26:11 EDT 2014

John and team,

I have an HW-16 and I just love the thing. Mine, like all of my old gear, is bone stock; personal preference for sure, and it performs fine. On occasion if a strong signal comes through, I just back down the RF gain control - that's why its there. 

The stuck slug is likely because its broken and the tiny sharp edge along the break line is digging into the coil form. I've had very good luck carefully drilling them out - small size bit and slowly work up. You get to a point where the slug will disintegrate and all you need do is clean out the remains and put in a new slug. You just need to be very careful and patient. 

The CW side tone note is ugly as per previous posts and I tried different resistor combinations to change the tone but ended up unsoldering the neon bulb and relying on the tone from my Heath HD 1410 keyer. 

As for power out I usually get about 40 to 50 watts on 80 and 40 and about 30 on 15. That's pretty consistent with the many HW-16's I have had over the years. Plenty of power to work DX and locals. 

I love the true QSK operation and find the receiver quite satisfactory...Obviously it would be nice to have some selectable bandwidths but then again the radio was designed to be relative cheap and easy to use. A novice rig. 

I fully respect anyone's desire to make mods and changes but I find the radio works great as built/designed and its short comings due to its 50 year old design and market price point objectives, are part of the fun! I really don't see a need for any mods to allegedly increase the receivers gain. I'm always concerned about any downstream effects such mods could introduce. In other words, is the cure worse than any perceived disease the radio may have? Last year I decide to work stations strictly using the HW-16 and an all band wire dipole just like I did as a kid back in the day. Tons of fun and a lot of DX and local contacts. Filled up many log sheets using the little beast. Never had any complaints from any of the stations I worked. 


  ----- Original Message ----- 
  From: John Klingelhoeffer 
  To: heath at puck.nether.net 
  Sent: Tuesday, March 11, 2014 1:13 AM
  Subject: [Heath] HW-16 update and additional question (11 MAR 14)

  Thanks to all who responded and gave comments and suggestions to the questions regarding the HW-16 refurbishment.  Most were very helpful.  I still have a locked slug in the 15M het oscillator coil form in the receiver that I may have to break out and retune with an external capacitor.  Silicone spray was not the answer.  That 15M LO level is a lot lower than 40 and 80 M.  On the transmitter side, I seem to get 50-60 watts out on all three bands so I'm happy, happy, happy about that.   

  The comments I have seen previously on the reflector about carbon composition resistors increasing in value on this old equipment is very important to heed.  So far, of those removed or tested, all have been 15-20% high in value.  Some also had very little 'headroom' in their dissipation.  The order to the electronics parts place is already in process.  

  Okay, so I won't say this is the last problem I'll post, but it is so far a vexing one.  At even moderate audio levels, a strong station will cause something - I think the audio output tube - to regenerate the received tone.  It sounds like the tube is oscillating in synchronization with the incoming CW and producing a strong keyed tone - sort of like a locked oscillator.  It ends up being a LOT louder than the signal level.  

  The troubleshooting instructions in the manual talk about the output transformer plate (blue) lead being too close to the PCB (and hence the grids of the audio amp tube) and causing 'howling'.  I would not characterize this as howling (unrestrained audio feedback) - the oscillation only happens when the strong CW signal is there and ceases between dits and dahs.  It's a keyed audio oscillation.  

  Just in case, I moved the blue transformer lead all the way to the edge of the chassis per the troubleshooting hint, and I also shielded it with the braid from of a piece of RG-59 cable.   However, no joy.  Still as bad as ever.  Also tried to replace the audio tube cathode electrolytic capacitor since I wasn't sure I'd changed that recently.  No change.  I performed the tube socket voltage tests and all were within a couple of percent.  

  Until this gets fixed, I'm not going to attempt any of the increased gain mods for the IF and RF amps as they would be counterproductive.  But, it needs to be fixed else the radio will be pretty useless.  Anyone seen this before and found a fix for it?  I don't remember this sort of thing happening on the one I assembled and used back in 1968-1970.  

  Should I just take a piece of insulated solid #16 buss wire, bring it up absolutely vertically from the PCB plate connection, and then route it over to the vicinity of the transformer before connecting to the blue transformer wire on a terminal strip under the transformer mounting screw?  I can't think of any way of getting it any more quickly away from the PCB and putting space between it an the tube grids.  I could use Teflon coaxial cable to make this a shielded run as well.   Other thoughts?

  Thanks and 73       John...   WB4LNM


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