Marantz 2130 part II
Below is the aligned frequency response of the 2130 post detection filter being swept with an HP 3585A spectrum analyzer. The response shown is after the flattest response of the composite can be achieved. The first dip is 114kHz (3rd sub-carrier harmonic) but the next one is at about 165kHz, moving the 2nd dip to 190kHz (5th sub-carrier harmonic) will screw up the composite flatness. As it is, there is over 35dB attenuation at 190kHz. We don't have IBOC here in Canada so I can't test how resistant the 2130 is to IBOC-induced noise.
PT200 board fully recapped. The 2130 has 2 discriminators, one is for audio and the other for tuning that feeds the scope input and quartz lock.
The 2130 has 2 IF modes. In wide mode it employs 2 IF filters, a Toko LC filter (F201) and a Murata SAW filter (F202). In narrow mode it uses 2 Murata GDT wide low loss ceramic filters "ML" (F203 & F204), and both SAW filters (F205 and F202). Ceramic filter F206 is employed for the 2nd discriminator.
P300 MPX board recapped. The NJM4558 op amp that follows the HA11223W was updated to a newer NJM4580.
PT00 buffer amp and mode switch board recapped. Again the NJM458 was replaced with an NJM4580. Silly tantalum capacitors used by Marantz for audio coupling were replaced with stacked polyester film capacitors.
One of the reason the owner wanted to have his Marantz 2130 rebuilt was the adoption of a new CRT replacement. This particular 2130 can use either the original Hitachi 50TB1 2" CRT or the more common surplus 2" CRTs. A new set of connectors was added while retaining the original CRT socket. The high voltage power transformer directly behind the CRT pin was moved further back and secured to make room for the longer CRT.
Front faceplate taken out and new CRT in place
Here's a 5sec 624kB video in MP4 format of the new CRT being tested off the chassis.
The old parts replaced.
Marantz 2130 below a McIntosh MR74, both ready to go back to its owner.
