[Premium-Rx] National HRO-600 help needed

[Brooke Clarke]

Hi James:

I've found that in most cases the reason that older equipment does not 
work is related to bad connections, see:
http://www.pacificsites.com/~brooke/HaT.shtml  If you have exhausted 
these simple remedies then . . .

Motorola has spun off a lot of their semiconductor parts to Freescale 
and OnSemi.
In the case of the ECL ICs I think they went to OnSemi.

These are a part of the MECL-10K line (Motorola Emitter Coupled Logic) 
which are listed here:
http://www.onsemi.com/site/products/parts/0,4454,381,00.html

I think a little work matching the number of pins and location of Vcc 
and ground will get you to the data sheets.  Once there a logic probe or 
scope may be all you need to find a bad IC.   The output from an AND 
gate that has a pulsing input should be a pulsing output, but the output 
from an OR gate with a pulsing input will only pulse when the other 
input is high.

If the above works for you we can discuss the meal details.

Have Fun,

Brooke Clarke, N6GCE

-- 
w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
http://www.precisionclock.com



James C. Garland wrote:

> Hi Gang,
> I;ve recently acquired a National HRO-600 VLF/HF receiver that I need 
> to repair. First, since this is a seldom-seen receiver, I'll supply a 
> few facts. The HRO-600 was the last receiver made by National, (in the 
> 70's), and followed the HRO-500.  It sold for around $6K and was thus 
> intended for government and military users. It covers 16 kHz-30MHz, 
> with a motorized preselector that provides front-end selectivity. It 
> has digital readout, 6 selectivity settings, 3 AGC time constants, and 
> receives SSB, CW, AM, with provisions for FSK.  It is built to 
> mil-spec standards, with teflon wiring and very high grade printed 
> circuit boards.  You can see a photo of it by Googling on HRO-600.
>
> The problem with my radio lies in the first injection circuit, which 
> is supposed to supply a (synthesized) 56-84 MHz signal in 1 MHz steps 
> to the first mixer.  This circuit uses Motoral MC1000-series ICs, 
> which are long discontinued. Unfortunately, I don't have the circuit 
> diagram for the synthesizer (the manual only supplies the mainframe 
> diagrams and not the board-level diagrams.)
>
> So, realizing this is a long shot, here's what I'm looking for. First, 
> if anybody has one of these receivers, I'd love to hear from you. And 
> if you have the circuit diagrams of the circuit boards, I'll buy you 
> dinner at a fancy restaurant.
>
> If you don't have the diagrams, however, I'll settle for data sheets 
> or specifications on the following Motorola ICs: MC1010P, MC1013P, 
> MC1023P, MC1027P, MC1039P.  These chips were from an early Motorola 
> MECL family. I've searched the web in vain for the pinouts and data 
> sheets, without which I can't make a start on repairing this beast.
>
> So any help or other info on this interesting radio would be most 
> appreciated. Incidentally, my radio works fine in the VLF range (16 
> kHz-1MHz) and hears like gang-busters.  (The synthesizer is only 
> needed above 1 MHz.)
>
> Thanks!
>
> Jim Garland W8ZR
>
>
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