[Hammarlund] HQ 170 vs RME 6900 alignments

[Rocco Lardiere]

Craig,

I made the following notes in the manual for my 6900 for the 57 kHz
alignment, which must be the one that gave Chuck a problem:

The manual says this for the signal generator connection:

"High side directly to lug on T4.  See illustration on page 10.  Low side to
chassis."

My notes state:

"Under T4 subchassis - left side - blue wire - use a mirror!"  I think I
used a mini grabber on the wire.  No removal of anything.

And for the output indicator, the manual states:

"VTVM, DC probe to junction of R61, R62, R63."

My notes say, "at terminal strip adjacent to T9 - or can use S meter!"

I used a Hi Z scope, not the VTVM, BTW.

So I did the alignment, and it worked out well.  I do NOT remember it being
that difficult.  If you want a DIFFICULT alignment, try a Hallicrafters
FPM-200 (first you have to OBTAIN one).   The access is truly challenging.

One other thing about this receiver that I did not see in Chuck's article:

If you like the 6900 AGC to work in the CW mode, the mod is VERY easy - the
mode switch grounds the AGC line in CW at one terminal - just remove the
jumper under the chassis (black wire to the electrolytic/teminal strip) and
jumper between the USB and CW terminals at the switch.

After this mod, I really like this receiver on CW.  Before - good way to
blow your ears out.

All in all, the 6900 is in the same class as the HQ170, performance wise.
In my opinion, the alignments are equally challenging - not THAT bad.

The 6900 is a fun radio to use, and the "look" is cool.  Mine has the
original bright silver main tuning knob.  But I like the 170 look, too, and
they are a lot easier to find in good condition.

73,

Rocco N6KN

----- Original Message ----- 
From: "Craig Roberts" <crgrbrts at verizon.net>
To: "lou de beer" <lou.de.beer at general-net.com>; "Hammarlund"
<hammarlund at mailman.qth.net>
Sent: Friday, December 10, 2004 9:28 PM
Subject: Re: [Hammarlund] RE:HQ 170 alignment


> If I remember correctly there's a resistor lead attached to pin 7 of V2
> that's pretty easy to clip onto.
>
> If you want to learn of a REAL alignment challenge, get this month's
> (December 2004) issue of Electric Radio and read Chuck Teeters'  story
> about his RME 6900 receiver rebuild. In order to attach the signal
> generator during one step of the IF alignment, you've got to get into
> the belly of a sealed sub-chassis which involves, among other things,
> removing the front panel.  That's when you're tempted to live with what
> you've got!
>
> Oh, in that same issue of the magazine there's a photo of my little
> shack on page 17.
>
> Good luck,
>
> Craig
> W3CRR
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