Model 800 Acquired Yesterday!

[Joseph W Strickland]

Yesterday, following a Vintage Antique Radio & Phonograph Society (VRPS) meeting in the Dallas, TX area, I visited the home of one of the club directors. He gave me two items completely free! I now have a Silvertone AM/FM/SW radio-phono-wire recorder console and an E H Scott model 800. I worked on a model 800 years ago for a good friend and the only thing wrong with it at the time was a shorted bypass capacitor in the FM IF strip. All its tubes were still good.

I am looking forward to restoring this E H Scott model 800. This one may be an early version of the 800. It seems to only have 3 IF stages in the FM IF rather than 4. I need to check closely and take some pictures of the units. I also will look for the serial number and any date codes on components to get an idea of when this unit was made.

Unfortunately there is no electro-dynamic speaker with this one, nor is there a cabinet for it. If anyone knows of a source for the speaker, please let me know. There is also no record changer or turntable with it, so that is another item to search for. I think I still have a Garrard RC-88 changer somewhere in the attic. I need to search to find it or else locate a suitable replacement turntable.

Joe

[Joseph W Strickland]

Here are the first photos of the units if they will attach. I had to straighten some pins on the interconnect cable plugs. They were bent.

Joe

[Joseph W Strickland]

I found the detail information on the back of the radio tuner chassis:

Model 800  1035, so I assume it is serial no. 1035.

The power supply chassis has this information stamped on the end bell of the power transformer:

91-B-423 followed on a second line; 306604 is this a date code or manufacturer EIA code? The two chrome plated chokes? just say Stancor on them.

Thanks to contributors for the collection of technical data on this site! This is excellent work by fellow members.

Joe

[David C. Poland]

You have the early version. Some changes were made at serial number 2000,

The speaker normally seen is a 15 inch with a tweeter suspended in the middle of the big cone - thus is a co-axial.   The set powers on by a relay. The speaker plug is in the AC circuit to that relay and so the radio can't power up without the speaker.  Eventually the earlier field coil version speaker was replaced in later production by a permanent magnet version speaker containing a power resister inside the bell cover in place of the field coil. The later version looks like the early version, but the bell cover is plastic instead of metal,  and it is backwards compatible for the earlier chassis.  Both painted the same darkish blue-green.

[David C. Poland]

800B speaker - front photo

[Joseph W Strickland]

David;

Thanks for those pictures of the speakers and the extra information. I had an e-mail from the previous owner and he did say that he received the unit without the OEM field core speaker. The power supply circuit was completed using a dropping resistor on the back side of one of the sockets on the chassis. He then used a permanent magnet speaker for the sound reproduction.

When I worked on an 800B years ago for a friend, his unit was a later model with a permanent magnet speaker. Do you know at what serial number sequences the changes you mentioned were made?

Were there other changes made to the units to improve performance in any way?

Thanks again.

Joe

[David C. Poland]

Circuit changes (not affecting the speaker or field coil specs)  began with Ser# 2000 according to documentation.  One change was the voltage specs for the for the AM/FM relay and also for the power on/off relay.  There were some more changes after ser# 4000.  There exists a blue cover compendium over 100 pages that include both Scott info and Riders info and makes note of such production changes. Worth while if you can find a copy. 

You need to have the owners manual to avoid frustration operating the radio. Example - for the radio to switch between AM and FM, a couple controls must be in proscribed position, 

The coax speakers are by Jensen according to my notes. Scott also offered a Stephens 15 inch speaker without tweeter according to my notes but I have never seen one.  The field coil substitution was much later, using a 675 ohm power resister  and so the later speaker can be used on earlier sets, and vice-versa. Incidentally, the tweeter is wired not to operate on AM stations & short wave. 

I restored an 800B some years ago for someone. A lot of work, but it sounded really good.

[Norman S Braithwaite]

I have seen one of the optional Stephens speakers.  Some of the very earliest 800B speakers were supplied by Magnavox.

Norman

[Joseph W Strickland]

So far it appears that the best way to go is to find appropriate replacement speakers. I know that the radio uses 6L6G output tubes. The service manual says it is rated at 25W so speakers capable of handling that and 40W maximum will be needed. I may go with an acoustic suspension type. I note that the tweeter was to be turned off on AM, so that is an added feature I will have to investigate. It must somehow be controlled by the RF band selector switch and also by whether phonograph or FM is selected. I am guessing that either there is wiring that cuts off the signal to the tweeter or a high frequency roll-off filter is engaged in AM/SW functions. I can see where such a filter could be included in the output of the AM detector circuit.

For cabinetry, it seems easiest to make a custom cabinet to place this unit in. After looking at some of the sets at Larry Lindsey's house, I am leaning toward making one that has the radio tuner chassis at the top with a top lid that will lift to show the chassis. Below that I might place a Garrard RC88 changer and then place the Pwr Amp/FM IF/Pwr Supply below that. A suitable heat shield/deflector would be needed above the last chassis. A speaker compartment at the bottom or possibly a separate speaker cabinet with all of the cabinetry made of the same wood type and finished the same way. I might look at some of E H Scott's various cabinets for ideas.

It is interesting that there was a connection to Magnavox.

Joe

[Joseph W Strickland]

After reading the 2nd set of the 800B Tech Service manual I see that there is an AM/FM relay and that one function it serves is to connect or disconnect the tweeter. It turns out that the tweeter is only used in FM mode. Even the phonograph function disables the high frequencies and the 15 inch main speaker reproduces all the audio. On SW broadcasts at maximum sensitivity adjustment there is a noise filter that limits noise impulses in the audio. I see this feature only on high end communication receivers such as Hallicrafters and National receivers.

Joe

[Joseph W Strickland]

After checking the information in the Tech Service Manual, I can see that this receiver is definitely one of the early units likely in 1946 because its FM IF/Pwr Amp/Pwr Supply chassis only has one 5H choke in the power supply.

Thanks to this group for providing such comprehensive service information on these!

Joe

[Norman S Braithwaite]

Serial number 1035 was most likely manufactured in April of 1946.  The single choke is a determining factor for the early version but an additional choke was added to many early version amplifiers.  A better indicator of the early version is the voltage regulator tube being located next to the FM detector tube.

Norman

[Joseph W Strickland]

Norman;

I think you meant the VR tube is next to the 1st FM IF tube. In any case, that certifies it as being in that period of manufacture. I do believe that this one was supplied with the electrodynamic speaker originally since it was eventually modified by adding two 1500 ohm 25W resistors to substitute for the missing field coil when a replacement speaker was implemented later.

I was only about 3 years old at the time this unit was produced. I have learned to appreciate these wonderful radios as an adult.

Joe