[Elecraft] OT - Heath CW Twins

[N2EY at aol.com]

In a message dated 10/6/07 12:07:38 PM Eastern Daylight Time, gibson at alma.edu 
writes:


> According to 
> Chuck, the HR-1680 was released in the Fall of 1967, 

I think he meant "fall of 1976". 

The first advertisement for the HR-1680 that I could find was QST for 
October, 1976. The ARRL Product Review came out in January 1977.

1967 was the year of the HW-100 and soon after the HW-16. Much too early for 
the all-solid-state HR-1680.

The Product Review says the VFO stability deserves special note, as it was 
measured as under 75 Hz from cold start to stabilization, and less than 20 Hz 
per hour after that. 

Using the SSB-bandwidth filter (CW selectivity is provided by an active audio 
filter),
the rx noise floor was measured as -137 dBm, BDR of 108 dB, and IMD two-tone 
IMD as 82 dB.

The review notes some of the corners that were cut to keep the price down 
($200 range). The RF circuits are diode switched, the IF xtal lattice filter is 
only 4 poles and made of discrete components rather than packaged, and the 
builder assembles the VFO. Only the first 1 MHz of 10 meters is covered, and there 
is no provision for more band xtals nor other IF filters. 

Since the receiver predates WARC-79 by several years, there's no 30, 17 or 12 
meter coverage.

The HR-1680 seems to me to have been meant as a replacement for the HR-10, 
but with much better performance and features. But at over $200 for the kit, I 
don't recall it being a big seller. If you wanted a hamband receiver, a used 
Drake 2B could be had for about that price or less, and offered a lot more 
features. The HW-101 transceiver cost only about $100 more than the HR-1680, and 
needed a power supply, but the '101 was a full-scale 100-watt class CW/SSB 
transceiver, covered all of 10 meters, and could be set up with the optional CW IF 
filter. 

73 de Jim, N2EY


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