Not a good 6aq8 substitute.

[Carbsandcaps]

Looking for replacements for a pair of 6aq8 tubes in a kenwood tuner, I turned to the internet. I found a 6ev7 under a list of suitable replacements and they’re considerably cheaper. Well not so much. It works however it shifted the all the stations 30mhz up the scale! Anyway hopefully anyone looking for a 6aq8 replacement comes across this.

 

[spantou01]

NOS 6aq8s are not very expensive. See:

6AQ8 / ECC85, Dual Triode Vacuum Tube | Amplified Parts

New-Old-Stock (NOS) tube. 6AQ8 / ECC85 high-mu dual triode vacuum tube, a noval 9-pin preamp tube closely related to the ECC83 / 12AX7 family but optimized for VHF applications, making it a common sight in vintage FM tuners, radio receivers, and early hi-fi preamplifiers from the 1950s and...

www.tubesandmore.com

 

[larryderouin]

6DT8. Been using them for 15 years now in various Fisher receivers and a Sansui 1000A. No shift on dial.

 

[gadget73]

Used in an oscillator the tube's capacitance can be a significant factor.

 

[TriodeLuvr]

The 6AQ8 and 6EV7 have very different inter-element capacitance values. The 6DT8 is much closer.

Jack

 

[arts]

If you're in a pinch or just need a quick substitute, the 12AT7 works well. Requires a slight change to the heater wiring.
Virtually the same specs as the 6DT8, but without the heater mid-tap or internal shield.

 

[b_youngblood]

I use 6BQ7s in European FM tuners with decent success. There may be some minor decrease in sensitivity, but they work fine for local stations.

 

[egellings]

NOS 6aq8s are not very expensive. See:

6AQ8 / ECC85, Dual Triode Vacuum Tube | Amplified Parts

New-Old-Stock (NOS) tube. 6AQ8 / ECC85 high-mu dual triode vacuum tube, a noval 9-pin preamp tube closely related to the ECC83 / 12AX7 family but optimized for VHF applications, making it a common sight in vintage FM tuners, radio receivers, and early hi-fi preamplifiers from the 1950s and...

www.tubesandmore.com

Looks like a reasonable price to me.

 

[mike567]

radio electric supply 6aq8 cheaper and in stock.
LATE REPLY sorry

 

[P78]

Also, the link shows the 6AQ8s are out of stock at AES.

I have heard good things about vaccumtube.net. (Keep meaning to place an order with them but always run out of time to call during their business hours.)

In a pinch and for more money, you can get this type from TubeDepot.

 

[kvflyer]

Bob Dobush, Find A Tube has NOS for $8.00. No affiliation. If you open the spreadsheet, use Control+F and put in the 6AQ8 and it will take you to the location on the spreadsheet.

Tube Price List by Bob Dobush

docs.google.com

 

[gadget73]

https://vacuumtubesinc.com/ quite possibly have them too. I didn't check the pricing but the lists on their website may not be entirely up to date. Send an email and they will confirm pricing and availability.