[Hammarlund] More HQ129 X Tubes??

[Todd Bigelow - PS]

Andy Bullington wrote:

>Ok, I have downloaded the manual and ordered replacements for the paper and electrolytic caps for my soon to be arriving HQ 129 X. Thanks
>for the help Guido and Todd. 
>   Now comes the question of tubes. I'm of a mind to replace the whole set. Most of them are inexpensive. There seem to be differing opinions on this, however. What do you guys think? Use em or lose em?
>                      Andy W1AWB
>

Andy -

Others have said it pretty well - wholesale replacement of the tubes 
isn't really as good as it sounds. Rather than being like putting 4 new 
tires on your vehicle, it could more accurately be equated to stuffing 
new pistons into an old motor without first doing the required work. As 
pointed out, the radio was probably aligned with the tubes it now has in 
it, or most of them. Depending how they've aged and how many, if any 
have been replaced, you could be opening yourself up to a lot of 
annoying hassles trying to track down 'problems' in the radio that don't 
really exist. Better to test each tube for shorts and overall emission, 
then go from there. Like someone said, try subbing a known good tube for 
a suspected bad tube and see if it improves your performance. Tube 
testers per say are generally good for telling good tubes from bad, but 
not perfect nor the final say. How a tube performs in your radio is what 
really matters. Many have had experiences of placing a 'new' tube that 
tested 'good' into a circuit, only to have it not work properly. Hmmmm...

While caps are more likely to be bad and need replacing, I'd suggest a 
similar approach here as well. Rather than going through with a complete 
recap, try going stage by stage, or circuit by circuit. Test the radio 
after each section is completed to see if it works! Maybe a wire got 
bumped to ground in the process and is grounding out your signal, maybe 
a resistor cracked inside and looks good but isn't functioning. Some 
guys go cap-by-cap, just to be really sure. You can decide what is best 
for you, but I'd certainly suggest a more reserved, balanced approach. 
Try to picture the bottom of your HQ-129X with all new Orange Drops in 
place after hours of hard work. You plug it in, it lights up but....no 
signal! ACK!! Where's the fault?

Electrolytics are another story. Not as many of them and they are more 
likely to be ticking time bombs if the radio hasn't been used regularly. 
These have the ability to take out some serious components like 
transformers, too. I have a few radios with original electrolytics 
inside, most still work fine but the caps should be replaced. Some have 
a little ripple in the speaker, others make it clear that it's only a 
matter of time (and luck). You can even cut the old 'Twist-Lok' can 
open, gut out the innards, then rebuild with new, smaller electrolytics 
and reseal it for a more authentic look. A few guys out there have 
brought this process to the level of a art.

One thing is for certain - it won't be an afternoon project to "do it 
right" as they say, but you'll gain some valuable experience as well as 
a certain degree of peace of mind in knowing you did it properly and can 
now enjoy the radio for years to come.

Good luck, keep us posted -

de Todd/'Boomer'  KA1KAQ