Swan Twins: 600-T, 600-R Custom, 600-S

From the Estate of AA5T

 Posted By: Bradley Stone (UncleBrad) on 12/21/2018

The Radio Shack 0 Comments 12/21/2018 

These excellent examples of the Swan Twins are from the estate of John Thuren, AA5T (SK) of Houston, Texas.  John had checked in to the 20M Swan net with these very desirable "big Swans" until a few years ago. 

AA5T (SK) Previous Owner

A big thanks to Eddie, NU5K, who handled John's estate and placed these on EBay.  He packed them well, knowing they are indeed an important find.  Also thanks to Jeff, WA8SAJ, who has written at least one article on the twins for Electric Radio, and - outside K4BOV - probably knows more about them than anyone else on the planet.

There were only 600 of the transmitters made, and 450 of the receivers, making these units extremely hard to procure.  Of the 450 600-R receivers produced, it appears to be unknown how many were the Custom (with the 16-pole crystal filter, factory AM filter and audio filter circuitry).  Surviving R600 Customs typically have missing or inoperative AM filters.

After providing the serial numbers of the units to Stu, K4BOV, he responded with some interesting information:

600R Custom #1802 built in May 1972 2nd series

600T #1909 Built in August 1971 2nd series

600S #1802 Built in May 1972 

I confirmed with Jeff, WA8SAJ, that the receiver has the hard-to-find original factory AM filter.  This particular set is in fine cosmetic and operating condition.  Some minor cleaning and detailing was all that was needed to get them back on the air.  Even the audio filter, which uses an impossible-to-find early integrated circuit, works well.  The twins have a high-quality feel to them, and are noticeably larger than the transceivers we're all so familiar with.  The receiver is surprisingly good.  The VFOs are very, very stable and smooth as silk.  These VFOs are set up in 2KC spreads.  To go above and below the default (0) segment, the operator must set the small scale to the left, using the calibrator.  This, plus the color-coded bands, which are very different than the typical Swan transceiver configuration and take some getting used to. 

The 600-T uses 6KD6 sweep tubes, which peak around 400W in my example.  The tuneup is similar to the transceivers, but peaks are also displayed on a very cool flourescent tuning eye.  Only a touchup of the idling current was needed to get it on the air.

Stu provides more information on the Swan Twins:

Swan completed the parts list for the Swan Twins in late 1969 and accumulated enough components and manufacturing set-ups to start building 100 sets - that is, 100 receivers and 100 transmitters. The first receiver and transmitter received serial number "1". Then the following went from 0101 thru 0199 for 600R receivers and 1201 thru 1299 for the 600T transmitters These are referred to as "run" or "series" one. 

Sales of the 600R was not as robust as the 600T. Remember back in the late 1960's and early 1970's many hams already had good receivers. There were 300 of the 2nd run with the receivers being numbered 1601 thru 1899 and the transmitters numbered 1901 thru 2199. However the 2nd run of receivers was delayed due to the reason above, sales of the 600T outpaced the 600R. This resulted in only 50 final receivers being built while another 200 600T's were produced - both of the final runs were given 5 digit serial numbers beginning with 18, 19 or 20. 

There were small variations among the 3 runs of the 600T and only two from the first to the last 600R (or 3 if you consider the difference between the standard and custom). 

The first run of 600T's had two screw-driver adjustable auxiliary load controls mounted on the rear chassis behind the PA compartment for accommodating low frequency antenna matching such as on 80 & 40 meter. Further factory testing and user feedback showed these extra capacitors were not necessary; so, were dropped on the 2nd series. However, the two access holes remained. Conversely, in the final run, there were no holes drilled.

Of interest, while looking up those numbers I saw that Herb Johnson's personal 600T was #1906 and a note that his widow Mimi had the unit for sale in 2000 a few months after he passed away.

Bob, W9RAN also has a set of these twins.  Stu provided some info on his:

600R Custom #1724 built in January 1972 2nd series(right after the plant reopened following the Christmas Holiday) 

600T #1912 built in August 1971 2nd series.

The pictures shown were taken prior to a careful cleanup.  I made no attempt to paint the cases, and took extreme care when cleaning the switches and pots.  Of course, finding replacement parts for these units can be extremely difficult or impossible.

My "new" twins now occupy the coveted Studio A, Row 1 position formally occupied by the Heathkit SB-104A lineup.

You can find a lot of information about these beautiful Swans in the 1972 Swan Catalog.


Posted: 01/20/2020
Comments: 0
Favorite VHF Nets

VHF NetsNet NameDayTimeFREQ/ModeEast Central Indiana 6M NetSunday8 PM EST50.140 MHz /USB...  READ MORE

Posted: 10/27/2019
Comments: 0
K5LYN's SB-10/Collins 310B/DX-60 Experiment

Below is a picture of my latest project.  After doing the transceiver thing, with a CE20A, mated to a SX-115, then the next transceiver project, a 10A mated to any Drake R4 series receiver, I had an idea.  Those transceiver projects have a lot of oscillators, and even the crystal oscillators can drift as they warm up, which requires re-zeroing the transmitter to the receiver from time to...  READ MORE

Posted: 08/29/2019
Comments: 0
Favorite HF Nets

All times are in Eastern unless otherwise indicated.  Frequencies are in Megacycles. Recommended HF NetsNet NameDayTimeFREQ/ModeSwan Technical NetWednesday2200 UTC14.2925 +/-  /USB3938 Traders NetWednesday8 PM3.938 / LSBBoatanchor NetWednesday7:30 PM CST3.870 / LSBWA9ZTY Vintage AM GroupSaturday7:30 AM3.885 / AMMidwest Classic Radio NetSaturday8:30 AM3.885 / AMSwan Technical NetSatu...  READ MORE

Vintage Manufacturers
Posted: 04/30/2019
Comments: 0
W1LSB Finds an EBay Treasure

I was first licensed as a novice in 1958, and the WRL catalog was really dominant in those days, with the Globe King, Globe Champ,  and all of the lesser models gracing its pages.  I had a Globe Chief 90 and often dreamed of owning the bigger iron in those pages.   I have since collected most of the WRL catalogs from 1954 to 1964, and the last one turned out to be an interestin...  READ MORE

Crazy EBay Prices!
Posted: 03/22/2019
Comments: 0
Crazy EBay Prices!

Below are some screen shots of incredible prices demanded by some EBay vendors.  Since posting an auction is free as long as the item is not sold, it costs nothing for the unscrupulous vendor to display their (unremarkable/filthy/nicotine-caked) wares as if they were priceless artifacts of distinction, having immense value.  It is truly within this online marketplace where prod...  READ MORE

The Radio Shack
Posted: 12/21/2018
Comments: 0
Swan Twins: 600-T, 600-R Custom, 600-S

These excellent examples of the Swan Twins are from the estate of John Thuren, AA5T (SK) of Houston, Texas.  John had checked in to the 20M Swan net with these very desirable "big Swans" until a few years ago. A big thanks to Eddie, NU5K, who handled John's estate and placed these on EBay.  He packed them well, knowing they are indeed an important find. ...  READ MORE

SDR for Vintage Radios
Posted: 08/09/2018
Comments: 1
SDR techniques for Boatanchor Radios

W9RAN started playing with RTL-SDR dongles about 6 years ago, and knew they were going to have a big impact on the radio hobby.   But since these $15 receivers only tuned the VHF and UHF bands, he designed a wideband upconverter to make HF coverage possible, and described how it worked in an article in Jan. 2013 QST "Cheap and Easy SDR".   The "RANVerter" as...  READ MORE

Posted: 03/04/2018
Comments: 0
2018 Cave City Hamfest

Barry, AC9NK and I attendended the 2018 Cave City hamfest, which was awesome this year.  The facility was packed, with lots of vendors.  We enjoyed the company of my friend Tom, N4LID for dinner the night before. Tom, who is blind, had not been able to get to the hamfest for many years.  You will find more pictures at the Kentucky Phone Net site.  A big thanks to Rod, N4ZIF, fo...  READ MORE

Vintage Manufacturers
Posted: 02/22/2018
Comments: 0
Remembering the Electra Company

For nearly five years, spanning 1978 - 1983,  I worked as an Electronics Technician in the original Bearcat manufacturing and service facility in Cumberland, Indiana.  Electra was one of the best places I've ever worked, and were among the many innovative consumer electronics companies which sprang up in and around Indianapolis.  Al Lovell, a former employee of Regency (also in ...  READ MORE

Care & Restoration
Posted: 02/08/2018
Comments: 0
Heath Tube-Type LMO Repair (PDF)

The tube-type Linear Master Oscillators (“LMO”) used in the Heathkit SB-Line equipment is a very stable and accurate means of controlling the frequency in the equipment. Unfortunately, as the units age, many LMOs develop a “warble” when tuning. This “warble” usually stops when the frequency control knob is not rotated. However, accurately “zero-beating&rdq...  READ MORE