The AM Forum

AMfone's Online AM Handbook => Receivers => Topic started by: W1VD on December 14, 2008, 07:59:49 AM



Title: Drake 1-A Receiver Test Results
Post by: W1VD on December 14, 2008, 07:59:49 AM
Receiver: Drake 1-A

Band    MDSBlocking DR   Two-tone DR
  (20 kHz)  (20 kHz)
80 meters   -130 dBm        109 dB    67 dB
40 meters   -130 dBm        107 dB    67 dB
20 meters   -130 dBm        107 dB    67 dB

AM audio S/N:

Additional measurements can be found at:

http://www.w1vd.com/BAreceivertest.html (http://www.w1vd.com/BAreceivertest.html)

Note: AM audio S/N, frequency response and distortion were not measured on the 1-A since it is designed as an SSB only receiver. AM detection, while possible using the product detector in exhalted carrier mode, is limited by the tight i-f bandpass.

Many thanks to Arnie, K1NFE for making this receiver available for testing.


Title: Re: Drake 1-A Receiver Test Results
Post by: Tom WA3KLR on December 14, 2008, 11:50:13 AM
Interesting Jay.  The DR performance of the 1-A is not too good.  It's interesting to note the positive progression of DR in those early Drake receivers versus the other receivers you have tested so far.

15 boat-anchor receivers tested.
Two-tone DR results:
1-A  13th place
 2A  8th place
 2B  3rd place.


Title: Re: Drake 1-A Receiver Test Results
Post by: W8EJO on December 14, 2008, 01:06:10 PM
It's interesting to note the positive progression of DR in those early Drake receivers versus the other receivers you have tested so far.

15 boat-anchor receivers tested.
Two-tone DR results:
1-A  13th place
 2A  8th place
 2B  3rd place.

R4 - ?
R4A - ?
R4B  - ?



Title: Re: Drake 1-A Receiver Test Results
Post by: Tom WA3KLR on December 14, 2008, 01:52:10 PM
Terry,

No R-4's have been tested.  Do you have one or more of these to loan Jay for this study? 

Bob Sherwood's Receiver Test Results List now ranks receivers by a 2 kHz. spacing DR test, critical for CW contesters.  Jay's testing uses Bob's older 20 kHz spacing since we are interested in AM mode only.

The only R-4 on Bob Sherwood's receiver test list is the R-4C.  The stock R-4C is near the bottom of his list.  However, a modified R-4C lead the top of the list for many years until the latest generation of solid-state receivers.

From Bob's data list, the R4-C is listed as 85 dB DR @ 20 kHz. spacing.  I believe that all of Bob's testing is done solely at 20 meters.  Jay has been testing at 80, 40 and 20 meters.  I average all of his results together.  I think this would place the R-4C in a tie for second place with the R390A; just my opinion.  I know you are curious about the -4, -4A, and B but just my 2 cents worth.


Title: Re: Drake 1-A Receiver Test Results
Post by: W8EJO on December 14, 2008, 02:06:56 PM
Terry,
No R-4's have been tested.  Do you have one or more of these to loan Jay for this study?  .  I know you are curious about the -4, -4A, and B but just my 2 cents worth.

I have an R4B that I might lend to Jay. The 4, 4A & 4B are much different animals than the C - very different radios really (dual vs triple conversion, LC vs crystal filtering, predominantly tube design vs hybrid, etc.).


Title: Re: Drake 1-A Receiver Test Results
Post by: W1VD on December 15, 2008, 08:57:44 AM
R4, R4A and R4B will be coming up shortly - all are available locally for testing.

Wish there were more hours in the day! The 1-A just finished took the better part of a day to get ready for testing. A couple ill conceived  mods needed to be rolled back, dipped silver mica caps in the 2.9 - 3.5 MHz i-f cans replaced, agc caps, etc, etc, etc. Oh yeah...an S-meter rebuild, voltage verification and finally an alignment. Most receivers tested don't need this much work but in order to ensure reasonable performance measurements some require 'special' attention.

The R4, R4A and R4B are in much better shape so they should move along quickly - yeah!


Title: Re: Drake 1-A Receiver Test Results
Post by: W8EJO on December 15, 2008, 01:26:59 PM
Good news Jay & let me add to the chorus:

Thanks for the great work!

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands