Anyone familiar with a Philco model 38-23? My issue is I am not getting any stations and getting a bad hum. It has been completely recapped, Bakelite casings also, and all tubes check well. Now a tell tale sign I did find was a black tar like substance around the Input Transformer. I realize this could likely be causing my humming but would that prevent me from receiving any stations? I do get volume control. I tap on the center terminal on the volume pot and I do get audio. I did tune the IF cans with feeding the 455Kc with an audio signal to the Grid of 6A8 and the RED terminal(antenna). It does respond when I adjust the pots. I did to their peak. The audio signal that came through sounded crappy but it was there and loud. I cannot tune the oscillator to the directed frequency of 18Mc. It just won’t do it. The hum is constant though. The tuning condenser is separated from the chassis with fresh rubber grommets so there is no obvious way it is shorting to chassis. This radio does have two output tubes and assume it is a push pull set up. Again, could my input transformer affect the radio’s ability to receive stations with this layout?
No I won’t be selling this radio on Ebay.
No I won’t buy any products from you, I already have a good trusted supplier.
I am not trying to sell any products either.
NO bickering please or you’ll get a time out like my three-year-old gets.
I just would like some knowledge from those who find this fun to do like me. Cute and cuddly boys, cute and cuddly….

Hi

Constant hum is usually caused by filter caps. Even though replaced did you notice negative on C49 and C34 do not connect together.

I would work on the hum first before trying to align your radio. Radio may require realignment after hum is eliminated.

Is alignment of the broadcast band correct? You mention 18Mc won't tune in. This higher frequency may require opening of trimmer caps?

Norm

:Anyone familiar with a Philco model 38-23? My issue is I am not getting any stations and getting a bad hum. It has been completely recapped, Bakelite casings also, and all tubes check well. Now a tell tale sign I did find was a black tar like substance around the Input Transformer. I realize this could likely be causing my humming but would that prevent me from receiving any stations? I do get volume control. I tap on the center terminal on the volume pot and I do get audio. I did tune the IF cans with feeding the 455Kc with an audio signal to the Grid of 6A8 and the RED terminal(antenna). It does respond when I adjust the pots. I did to their peak. The audio signal that came through sounded crappy but it was there and loud. I cannot tune the oscillator to the directed frequency of 18Mc. It just won’t do it. The hum is constant though. The tuning condenser is separated from the chassis with fresh rubber grommets so there is no obvious way it is shorting to chassis. This radio does have two output tubes and assume it is a push pull set up. Again, could my input transformer affect the radio’s ability to receive stations with this layout?
:No I won’t be selling this radio on Ebay.
:No I won’t buy any products from you, I already have a good trusted supplier.
:I am not trying to sell any products either.
:NO bickering please or you’ll get a time out like my three-year-old gets.
:I just would like some knowledge from those who find this fun to do like me. Cute and cuddly boys, cute and cuddly….
:
:

C49 has and is connected to its own floating ground. Verified it was not shorted to chassis ground. C34 is actually two capacitors in one. The ground for both of those I believe to chassis ground. I will verify that tonight. I will also change that to a floating ground if not already.
The mentioned 18Mc tuning is one of the tuning steps. It seems they tune the oscillator by tuning the SW freq of 18Mc. Note A in tuning instructions. So adjusting the oscillator is an issue because of not being able to find the second peak audio to tune to. This is something I need to look further into.
I do appreciate your help. I will eliminate the hum first then working on tuning. That makes sense. Please let me know if you have any other ideas on what’s going on. It does help.

Does anyone know if I have to tune to 18Mc? can it be another Freg in the Mc range? Important because my Freq generator has issues at this high range.

get it fixed?

:Does anyone know if I have to tune to 18Mc? can it be another Freg in the Mc range? Important because my Freq generator has issues at this high range.
:

Just to note. It's 470KC I.F. You may have just made a typo.

RJ,
Don't understand the 18mHz, except designer may have discovered setting the osc on a SW band first would then optimize the entire range covered by the osc. At an osc freq of 18mHz, RF should be tuned to 17.53mHz.
(Osc) 18mHz minus (RF)17.53mHz = 470kHz IF. Make sure the RF is tuned to 17.53 before adjusting the trimmer.

marv

:Anyone familiar with a Philco model 38-23? My issue is I am not getting any stations and getting a bad hum. It has been completely recapped, Bakelite casings also, and all tubes check well. Now a tell tale sign I did find was a black tar like substance around the Input Transformer. I realize this could likely be causing my humming but would that prevent me from receiving any stations? I do get volume control. I tap on the center terminal on the volume pot and I do get audio. I did tune the IF cans with feeding the 455Kc with an audio signal to the Grid of 6A8 and the RED terminal(antenna). It does respond when I adjust the pots. I did to their peak. The audio signal that came through sounded crappy but it was there and loud. I cannot tune the oscillator to the directed frequency of 18Mc. It just won’t do it. The hum is constant though. The tuning condenser is separated from the chassis with fresh rubber grommets so there is no obvious way it is shorting to chassis. This radio does have two output tubes and assume it is a push pull set up. Again, could my input transformer affect the radio’s ability to receive stations with this layout?
:No I won’t be selling this radio on Ebay.
:No I won’t buy any products from you, I already have a good trusted supplier.
:I am not trying to sell any products either.
:NO bickering please or you’ll get a time out like my three-year-old gets.
:I just would like some knowledge from those who find this fun to do like me. Cute and cuddly boys, cute and cuddly….
:
:

:RJ,
:Don't understand the 18mHz, except designer may have discovered setting the osc on a SW band first would then optimize the entire range covered by the osc. At an osc freq of 18mHz, RF should be tuned to 17.53mHz.
:(Osc) 18mHz minus (RF)17.53mHz = 470kHz IF. Make sure the RF is tuned to 17.53 before adjusting the trimmer.
:
:marv
:
:
::Anyone familiar with a Philco model 38-23? My issue is I am not getting any stations and getting a bad hum. It has been completely recapped, Bakelite casings also, and all tubes check well. Now a tell tale sign I did find was a black tar like substance around the Input Transformer. I realize this could likely be causing my humming but would that prevent me from receiving any stations? I do get volume control. I tap on the center terminal on the volume pot and I do get audio. I did tune the IF cans with feeding the 455Kc with an audio signal to the Grid of 6A8 and the RED terminal(antenna). It does respond when I adjust the pots. I did to their peak. The audio signal that came through sounded crappy but it was there and loud. I cannot tune the oscillator to the directed frequency of 18Mc. It just won’t do it. The hum is constant though. The tuning condenser is separated from the chassis with fresh rubber grommets so there is no obvious way it is shorting to chassis. This radio does have two output tubes and assume it is a push pull set up. Again, could my input transformer affect the radio’s ability to receive stations with this layout?
::No I won’t be selling this radio on Ebay.
::No I won’t buy any products from you, I already have a good trusted supplier.
::I am not trying to sell any products either.
::NO bickering please or you’ll get a time out like my three-year-old gets.
::I just would like some knowledge from those who find this fun to do like me. Cute and cuddly boys, cute and cuddly….
::
::
: