[Hammarlund] HQ140X

[GRANT YOUNGMAN]

I just did the alignment on an HQ-140X this past week.  Used a sweep generator and a scope with a log detector.  It was really instructive.

You can simply peak all of the transformers on the crystal frequency.  You will actually get a higher maximum IF output doing that, but you also will get a narrower “peaky”  passband with a funky shape rather than something with a nice symmetrical shape and a flat (well, really somewhat rounded) top.

Bill’s idea is correct — you really do want to try to get a symmetrical passband if possible.  The radio will sound better with greater fidelity.  It’s tedious to do by hand, but will give you a better result if you have the patience for it.  Z3 is the most critical to the overall shape.  Also the top core on Z4.  The bottom core on Z4 did not change the overall passband shape much, just the gain.

Do it the way the manual recommends.  One stage at a time starting with the last IF amp and moving towards the front of the chain.

Grant NQ5T


On Mar 24, 2014, at 1:44 PM, Bill Kulze <wak9 at cornell.edu> wrote:

> 
> 
> -----Original Message-----
> From: On Behalf Of radiomanL
> Subject: [Hammarlund] HQ140X
> 
> anyone attempted alignment with only a standard RF generator ? any ideas would be welcome 
> 
> andrew
> kd5pnt
> ___________________________
> 
> If you're referring to the alignment requiring a sweep, I used a scope on the DC diode load on a 129x. After finding where the xtal resonated I manually swept from 3kc down to 3kc up and kept adjusting to get both endpoints equal and the peak at center. Besides a scope it requires patience in a fair measure.
> 
> Bill
> W2NVD
> ______________________________________________________________
> Hammarlund mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hammarlund
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Hammarlund at mailman.qth.net
> 
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
> 
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html