I have a couple radios that use these. There doesn't seem to be a suitable replacement for them. I assume low noise?
It appears to be like a 6BA6 but 2.5 times its transconductance, or a 12BY7 in a 7 pin base.
I think the nearest replacement would be a 6CB6.
I think the nearest replacement would be a 6CB6.
Special? What do you mean?
It was made as an IF amplifier and limiter for FM receivers. It has a sharp cut off and the anode voltage of around 150volts.
7 pin B7G socket.
Nothing special that I can see.
It was made as an IF amplifier and limiter for FM receivers. It has a sharp cut off and the anode voltage of around 150volts.
7 pin B7G socket.
Nothing special that I can see.
Its transconductance in 9.5mS, much higher than an ordinary IF pentode.
The only "special" is controlled heat-up time. Otherwise, 6AH6, 6AC7, 6AJ7, 6Ж5П are slightly better. 6AH6 and 6Ж5П are pin to pin compatible.
You can use also 6Ж38П or even 6Ж1П, but with lower gain.
You can use also 6Ж38П or even 6Ж1П, but with lower gain.
Here is some useful book from Sylvania:
https://frank.pocnet.net/other/Sylvania/SylTubSubstManual1953.pdf
https://frank.pocnet.net/other/Sylvania/SylTubSubstManual1953.pdf
Thank guys for the info.
I have a couple pieces of Drake ham equipment that use these.
I evidently found some misinformation on these tubes.
I have a couple pieces of Drake ham equipment that use these.
I evidently found some misinformation on these tubes.
Wavebourn,
Thanks for the .pdf
But . . .
I miss my old Sylvania tube manual with the ring binder; pages turned nice.
CRTs, and later on LCDs are not the same as reading from a real book.
Thanks for the .pdf
But . . .
I miss my old Sylvania tube manual with the ring binder; pages turned nice.
CRTs, and later on LCDs are not the same as reading from a real book.
@ 6A3SUMMER
+1
I have 5 or 6 books of transistors directory and I can only work with that.
I retain the information better.
I'm looking for books on the tubes but it's not easy to find.
+1
I have 5 or 6 books of transistors directory and I can only work with that.
I retain the information better.
I'm looking for books on the tubes but it's not easy to find.
Many Drake receivers wire two heaters in series across a 12.6 volt winding. Their heater current's MUST match to avoid blown or under heated tubes. The controlled warm up characteristic is also highly desirable. It also draws 450 mA of heater current which is not too common.
The 6HS6 has a much higher transconductance than the more common 6AU6 or 6BA6. The transconductance of the 6HS6 is what determines the ability of the receiver to perform good in weak signal, especially on the higher frequency bands like 10 meters.
Some people have successfully used the 6AH6A or 6AH6WA, but it has a different pinout and requires rewiring the socket. I have used the 6EW6 in a Heathkit radio, but the radio must have pin 1 and 7 connected together (often the case) since these pins are swapped, AND you must add a resistor across the heater to eat the extra 50 mA.
I've not heard of using the 6AH6 in place of 6HS6 but that would be great if it works. NJ7P does list it as a sub, and it has the right heater current. Some people use 6AU6, but it is a 0.3 amp heater and 6HS6 is 0.45 so
Haven't looked at the heater wirings that close - I have a TR-3 here which uses a 6HS6 and also uses 12JB6 in the final. I didn't see any 6HS6 in a TR-4CW/RIT I have here at the office. I saw at least two in an R-4B; the R-4C dropped 6HS6 in later production runs in favor of 6EJ7. My R4-C uses 6EJ7.
Collins also used series / parallel heater strings in some of their rigs. I would love to dump the brutally hot running 6BF5 in my 51S-1 in favor of a 6AQ5, but can't do it *because* of the difference in heater current.
Win W5JAG
Haven't looked at the heater wirings that close - I have a TR-3 here which uses a 6HS6 and also uses 12JB6 in the final. I didn't see any 6HS6 in a TR-4CW/RIT I have here at the office. I saw at least two in an R-4B; the R-4C dropped 6HS6 in later production runs in favor of 6EJ7. My R4-C uses 6EJ7.
Collins also used series / parallel heater strings in some of their rigs. I would love to dump the brutally hot running 6BF5 in my 51S-1 in favor of a 6AQ5, but can't do it *because* of the difference in heater current.
Win W5JAG
Valves aren't designed out of boredom at work, but to meet a demand or create a demand. Demands change. Competition also causes change, usually for the worse in electronics.
The 6HS6 used in the R4-C was in the design of a receiver stuffed-up by cost-cutting to the point of absurdity. Drake was no different from say Heathkit...They surveyed the component-costs market for design/during design or it came to them. Valves were chosen on adequacy but also on cheapest cost. The 6HS6 was not in vast supply but it was used for the first 21000 sets...that's 42,000 tubes on top of the quantity anyone else used.
It's perhaps not too speculatory to suggest Drake may have bought 50,000 6HS6's and kept the balance of say 8000 for service or replacements. Maybe they extended the 6HS6 model to the bitter-end, around S no. 21000 when offered a swag of 6EJ7's...
When the 6HS6 became higher in price than the 6EJ7, the bean-counter philosophy on a set already well known to be riddled with defects in design.. used the 6EJ7.
Issues with the 6EJ7 included higher noise than desired and shorter life than the 6HS6. Sherwood and later his off-sider Satori set about a rectification business. The 6EJ7 was considered very poor as a mixer and a solid state design was marketed. The R4-C power supply was a monument to ineptitude, dropping 150 volts via resistor, to 12volts and essentially burning-up the p/s area. The curent demand kept the solid state supply down to about 10 volts (unregulated). The product detector was recommended be changed pre,at and post S mo. 21,000. The Amplifier (class A) drew so much current the power supply burned-out (literally)
Another problem with tube availability occurs when "Audiophiles" get frenetic over some valve or another and go on about some manufacturing aspect or manufacturer itself. One of the most important aspects, the speaker gets essentially marketing attention, power is addictive whereas a great result in past came from say sensitive Goodman's speakers and 10watts.
Today 'noise' considered to be 'music' is wanted and if the tubes in use are all 'top of the line' the perception is 'euphoria'. One can also get-off reading audio magazine 'hooks'. The other long ignored aspect is transformer design...power and audio although yes perhaps even 'most' amplifiers use direct coupling.
Mass production moved away from 'hi-fi' other than the words. In the re-emergence of tubes came all sorts of 'tube fantasies' promoted by audio magazines. As well, Russian 'direct replacements' are often not that at all. The 12AX7 is one however perhaps reasonable. I have a number of 12AX7's for example and I think its a 300B or some-such seen that latter sometimes for heading towards $2000/pair... Audiophiles want 'matched pairs'...which only lasts 'so long' and the set may have different bias' even to one tube. Cathode, grid and plate voltages should all be readily adjustable and were I designing an amp it would have switched- metering to all those figures. Components age and for example replacing one cap or one resistor may significantly chang the signal processing compared with the other side of a triode. "Matched-pairs' sounds good though and the prices double or triple, sometimes more.
I may as well sell all this stuff as I'm selling off my vintage amps soon (presumably eBay) and I suppose hundreds of tubes....keeping only what I need after repairing in the foreseeable future (If I have one LOL!!) at least 20 WW2 Receivers and some other sets.
I am presently in that R4-C mix-up and its overpricing and absurd US postal demands...One bloke wanted about $475 to send a 23lb set "USA' to here...another nearly $900 for the same thing...the place has gone stark-raving mad, we are being 'trumped' and currency Vs USA is ridiculous..
I'll get back to some simple sets from the 1950's-70's and sell off my collection to others who will enjoy even just having them. I may even get back to my turntables and old stones Beatles and other albums....get back to enjoying audio without hypertension (chuckles) You can catch me outside the forum on france007@onthenet.com.au for discussion/arguments on my perceptions . I may not be a regular visitor, simply because of 'pent-up demand all around me after 5 years of study. My Regards.
The 6HS6 used in the R4-C was in the design of a receiver stuffed-up by cost-cutting to the point of absurdity. Drake was no different from say Heathkit...They surveyed the component-costs market for design/during design or it came to them. Valves were chosen on adequacy but also on cheapest cost. The 6HS6 was not in vast supply but it was used for the first 21000 sets...that's 42,000 tubes on top of the quantity anyone else used.
It's perhaps not too speculatory to suggest Drake may have bought 50,000 6HS6's and kept the balance of say 8000 for service or replacements. Maybe they extended the 6HS6 model to the bitter-end, around S no. 21000 when offered a swag of 6EJ7's...
When the 6HS6 became higher in price than the 6EJ7, the bean-counter philosophy on a set already well known to be riddled with defects in design.. used the 6EJ7.
Issues with the 6EJ7 included higher noise than desired and shorter life than the 6HS6. Sherwood and later his off-sider Satori set about a rectification business. The 6EJ7 was considered very poor as a mixer and a solid state design was marketed. The R4-C power supply was a monument to ineptitude, dropping 150 volts via resistor, to 12volts and essentially burning-up the p/s area. The curent demand kept the solid state supply down to about 10 volts (unregulated). The product detector was recommended be changed pre,at and post S mo. 21,000. The Amplifier (class A) drew so much current the power supply burned-out (literally)
Another problem with tube availability occurs when "Audiophiles" get frenetic over some valve or another and go on about some manufacturing aspect or manufacturer itself. One of the most important aspects, the speaker gets essentially marketing attention, power is addictive whereas a great result in past came from say sensitive Goodman's speakers and 10watts.
Today 'noise' considered to be 'music' is wanted and if the tubes in use are all 'top of the line' the perception is 'euphoria'. One can also get-off reading audio magazine 'hooks'. The other long ignored aspect is transformer design...power and audio although yes perhaps even 'most' amplifiers use direct coupling.
Mass production moved away from 'hi-fi' other than the words. In the re-emergence of tubes came all sorts of 'tube fantasies' promoted by audio magazines. As well, Russian 'direct replacements' are often not that at all. The 12AX7 is one however perhaps reasonable. I have a number of 12AX7's for example and I think its a 300B or some-such seen that latter sometimes for heading towards $2000/pair... Audiophiles want 'matched pairs'...which only lasts 'so long' and the set may have different bias' even to one tube. Cathode, grid and plate voltages should all be readily adjustable and were I designing an amp it would have switched- metering to all those figures. Components age and for example replacing one cap or one resistor may significantly chang the signal processing compared with the other side of a triode. "Matched-pairs' sounds good though and the prices double or triple, sometimes more.
I may as well sell all this stuff as I'm selling off my vintage amps soon (presumably eBay) and I suppose hundreds of tubes....keeping only what I need after repairing in the foreseeable future (If I have one LOL!!) at least 20 WW2 Receivers and some other sets.
I am presently in that R4-C mix-up and its overpricing and absurd US postal demands...One bloke wanted about $475 to send a 23lb set "USA' to here...another nearly $900 for the same thing...the place has gone stark-raving mad, we are being 'trumped' and currency Vs USA is ridiculous..
I'll get back to some simple sets from the 1950's-70's and sell off my collection to others who will enjoy even just having them. I may even get back to my turntables and old stones Beatles and other albums....get back to enjoying audio without hypertension (chuckles) You can catch me outside the forum on france007@onthenet.com.au for discussion/arguments on my perceptions . I may not be a regular visitor, simply because of 'pent-up demand all around me after 5 years of study. My Regards.