Looking for someone to repair and align a Hallicrafters HA-5 VFO

[kc2hgc]

Hi Brian,
I was looking at the specs.on this vfo its kind of cool; as we all can see there are two oscillators. A mixer & power amp.

I can walk you through this trouble shoot if you like.
Here some basic checks.
Test the tubes,
Check tube Voltages,
Clean the band switches,I use rubbing alcohol,
The signal pass`s through these switches. Ill bet there dirty also try moveing the knob when checking for output..

Also this thing is cathode keyed: Do a cold ohm check from the cathodes of mixer & amp.
if there is an open the vfo will NOT have an output!

I just repaired a globe 775 and one of the band switch wafers was bad.
Get back and lets get this vfo working.

73   Steve

[KG0MN]

Thanks to Keith - K0GNW the VFO is back in operating condition.  What we found out or I should say, what he found out is that there are two different schematics for Hallicrafters HA-5. Looking at the cathode of V1A - 1/2 6U8A on my schematic it has a R2 - 120 ohms resistor and C8 a .005 capacitor that comes off of the cathode of the tube on pin 7.  The schematic that Keith found has pin 7 of that tube going directly to ground.  By doing removing those components the oscillator came to life and he was able to align it exactly as it stated in the manual.

I know Keith reads this forum and I want to take this opportunity to thank him for being so patient when it came to me asking questions and learning more about how it operates.  Now I am left to get a microphone see how it sound on AM as well as CW.  I also want to thank every on the forum for the advice they gave me and the genuine way you made me feel at home.

Thanks to everyone and happy 2013 and may you find a prize boat anchor of your own liking.

Kevin Elliott - KG0MN

[n1uvi]

Good catch
thanks for that info
you know didn’t even think of it before
but there was an errata sheet that accompanied the original
manual that stated that after the instruction manual was printed
but prior to production certain minor electrical changes were made
in fact item #1 on that errata sheet deletes R2 and C8
nobody put two and two together and knew you had access to
original schematics   
Very glad to hear you got it working hope to hear you on the air someday 73

[KG0MN]

I thought I would come back and let you know that the HA-5 VFO was fixed and then combined with the HT-40 and SX-140 Receiver I was able to get WAS with the old gear a number of DX stations as well.  I also found another HA-5 VFO that is real nice shape but when I got it it has AC hum that over-riding everything, so I got a new 3-stage capacitor from Hayseed Hamfest and then fixed that issue and the cap is the same size as the original.  Was at hamfest in California a while back and picked up an HT-40K transmitter and since the transmitter and VFO are is such good shape I think I may pickup a Drake 2B or C for the listening portion.  I have even done a bit of AM on the HT-40 and got decent reports so this project is finished and I may sell this setup of Ebay to finance the next restoration project now that I have learned a few things.

Thanks again to all those that helped me initially.

Kevin -KGØMN