04-16-2017, 04:26 PM
...bad news
I turned the receiver over, connected two speakers, plugged it in through my Variac, and slowly brought it up to 115 volts.
It's Alive!
[Image: http://www.philcoradio.com/images/phorum...00_021.jpg]
Those new Hayseed Hamfest caps certainly look good on top of the chassis.
[Image: http://www.philcoradio.com/images/phorum...00_022.jpg]
But here is the bad news:
I let it play for several minutes, tuning across AM and FM bands, and it was sounding great.
All of a sudden, I started noticing a pronounced distortion in the sound!
I looked at the 6П14П tubes, and one of the poor little Russian tubes had a glowing red plate.
I immediately turned the thing off.
The distortion could be the result of audio coupling caps dying (I did not replace any of the brown caps that look like brown Orange Drops), but the glowing red 6П14П concerns me. It looks like I will be forced to install the Dave Gillespie IBAM mod in this receiver if I ever want to use it for any length of time. In a nutshell, this allows for individual bias settings for all four output tubes so they run at peak efficiency, and to avoid such red-plate situations.
It's probably a good thing I have another set of NOS-NIB 6П14П-EB tubes on their way here from Ukraine. (Maybe I should have bought two sets?)
Well, at least I made my goal of hearing this receiver play in time for my birthday (I actually beat that goal, having heard it for the first time last night). But this unit will require more work.
I need to order some CL-80 inrush current limiters for this receiver as well as my Fisher 400 and 500-B. I shall also order the necessary parts to build an IBAM board for this receiver.
I turned the receiver over, connected two speakers, plugged it in through my Variac, and slowly brought it up to 115 volts.
It's Alive!
[Image: http://www.philcoradio.com/images/phorum...00_021.jpg]
Those new Hayseed Hamfest caps certainly look good on top of the chassis.
[Image: http://www.philcoradio.com/images/phorum...00_022.jpg]
But here is the bad news:
I let it play for several minutes, tuning across AM and FM bands, and it was sounding great.
All of a sudden, I started noticing a pronounced distortion in the sound!
I looked at the 6П14П tubes, and one of the poor little Russian tubes had a glowing red plate.
I immediately turned the thing off.
The distortion could be the result of audio coupling caps dying (I did not replace any of the brown caps that look like brown Orange Drops), but the glowing red 6П14П concerns me. It looks like I will be forced to install the Dave Gillespie IBAM mod in this receiver if I ever want to use it for any length of time. In a nutshell, this allows for individual bias settings for all four output tubes so they run at peak efficiency, and to avoid such red-plate situations.
It's probably a good thing I have another set of NOS-NIB 6П14П-EB tubes on their way here from Ukraine. (Maybe I should have bought two sets?)
Well, at least I made my goal of hearing this receiver play in time for my birthday (I actually beat that goal, having heard it for the first time last night). But this unit will require more work.
I need to order some CL-80 inrush current limiters for this receiver as well as my Fisher 400 and 500-B. I shall also order the necessary parts to build an IBAM board for this receiver.
--
Ron Ramirez
Ferdinand IN
