If the linearity and accuracy of the other bands is fine, you should be able to get satisfactory results from just peaking the trimmer cap of the first tuning condensor section, otherwise you could peak and align that whole section with just a little more time if the on trimmer is not enough, but giving consideration to the age, check the paper caps for them losing capacity from drying out. Also check voltage at the plates of the tubes in the RF and IF sections (resistors may have shifted in value slightly). Outright replacement of the paper caps is really not that bad of an idea either. Plus going through and checking the alignment of each band and tweaking the IF's to peak is usually well worth the effort.
:band D's receive is very weak. I've cleaned the band select contacts. So what should I do next?
Much Thanks and Regards,
Greg Hamilton
:Hi,
:
:If the linearity and accuracy of the other bands is fine, you should be able to get satisfactory results from just peaking the trimmer cap of the first tuning condensor section, otherwise you could peak and align that whole section with just a little more time if the on trimmer is not enough, but giving consideration to the age, check the paper caps for them losing capacity from drying out. Also check voltage at the plates of the tubes in the RF and IF sections (resistors may have shifted in value slightly). Outright replacement of the paper caps is really not that bad of an idea either. Plus going through and checking the alignment of each band and tweaking the IF's to peak is usually well worth the effort.
:
:
:
::band D's receive is very weak. I've cleaned the band select contacts. So what should I do next?
It is possible that the 12BE6 and 12BA6 tubes are weak in that they are not performing as well as they could at the upper frequency range, but you should check voltages with the set on the upper band just to see if there might not be another issue with a resistor shifting value as some of those can shift quite a bit. I would look at R9 especially, because this one can have a tremendous amount of influence on the sensitivity of the radio.
In genral, up at the top end of the tuning range of the set, I have a couple ofmore sophisticated Hallicrafters, and they don't pick up that upper area on yours where the CB and 10 meter rigs are being used, they just don't have a lot of power, or just do not use a whole lot of power. Most 10 meter users try for the local repeater, so they do not normally use that much. There are exceptions to that, but in general, most of what you are going to hear is fairly low power. The only way to compensate for that is a longer antenna, or a more specialized antenna such as a trap dipole tuned to that portion you want to listen to. Otherwise most shortwave above 20Mhz is going to be limited to about a high end of 24 Mhz, and many of those stations are not expecting to be routinely heard on another continent. The big european powerhouses pretty much stay below 20 Mhz.
:Thanks John for the input! I did the full alingment found in the manual section on this sight. It mad a big difference on all the bands. Band D is still very attenuated relative to the other bands. I will try replacing the caps as you've sugested. Do you think the tubes might be weak?
:
:Much Thanks and Regards,
:Greg Hamilton
:
:
:
::Hi,
::
::If the linearity and accuracy of the other bands is fine, you should be able to get satisfactory results from just peaking the trimmer cap of the first tuning condensor section, otherwise you could peak and align that whole section with just a little more time if the on trimmer is not enough, but giving consideration to the age, check the paper caps for them losing capacity from drying out. Also check voltage at the plates of the tubes in the RF and IF sections (resistors may have shifted in value slightly). Outright replacement of the paper caps is really not that bad of an idea either. Plus going through and checking the alignment of each band and tweaking the IF's to peak is usually well worth the effort.
::
::
::
:::band D's receive is very weak. I've cleaned the band select contacts. So what should I do next?