Author Topic: Packard Bell RPC-66  (Read 1166 times)

Motorola Minion

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Packard Bell RPC-66
« on: October 02, 2017, 11:30:03 AM »
I'm working on this solid state console that probably needs caps among other items. The voice of music changer is branded PB also but uses an odd cart.

Has anyone here worked on a PB before. I have a Sams 905 for the RPC-56, hoping its close. Pictures once I open it up.
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Dave

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Re: Packard Bell RPC-66
« Reply #1 on: October 02, 2017, 01:39:14 PM »
Dave,
Search for  RPC 66 came up referenced in Sams 902-5.
Dated 1967.
It gives models covered as RPC 50/52/54.
Assume the chasses stayed the same for yours.

HFF

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Re: Packard Bell RPC-66
« Reply #2 on: October 02, 2017, 06:23:57 PM »
Only the kind with hot bottles.
-- Aloha, Ken

No Console Left Behind!

Motorola Minion

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Re: Packard Bell RPC-66
« Reply #3 on: October 03, 2017, 01:50:25 PM »
I opened it up and took a few pictures. Checking ebay, this was not a top of line model with separate amp but all in one receiver chassis very similar to a mid-level Magnavox Astrosonic. The unique Cartesian AM - FM dial was used on the more expensive models.

On another note, I got an address from an ebay item of 1905 Armacost Ave in Los Angeles. Using streetside, the low brick building is now a charter school, so it was too solid to demolish but in the 1950s(?) it was pretty modern-cool.

I recall Packard Bell TV's as prizes on "the price is right game show". But like a Curtis Mathes, I never saw one in person. 

Pics on next post

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Dave

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Re: Packard Bell RPC-66
« Reply #4 on: October 03, 2017, 02:33:38 PM »
Before I remove for bench testing and repairs, here it is.
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Dave

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Re: Packard Bell RPC-66
« Reply #5 on: December 01, 2017, 01:54:48 PM »
I finally got the chassis re-capped with all 105 degree C caps from justradios. Chassis build quality made it a delight to work on, as good as a Zenith but with a few PC boards like a Magnavox.
 
All this chassis electrolytic caps measured higher than marked, sometimes double. A response post to one I made on another forum about this odd finding, suggested that as aluminum oxidizes, it expands and decreases distance between "plates", raising capacitance before it fails. The voltage breakdown test failed even at 25V for the few I tested, on my old school ap tester.

The original 1000 mf black power supply caps were "Nashville electronics", a few were Ducati, but most of the blue ones were Nichicon. Being 50 years old, even better quality caps go bad.

One of the Mallory pots, second from left (volume with push-off power), was mashed down hard a few times, breaking the tiny tabs holding it together. The separation is visible on the middle section, such that the wiper contact could have separated. i soldered a pair of #18 copper "straps" from front to back, clamping it as I did so.

 Its ready to go back in the cabinet.
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Dave

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Re: Packard Bell RPC-66
« Reply #6 on: December 01, 2017, 02:17:52 PM »
Had to replace the idler wheel in this V-M changer, it was so glazed, I could not bring it back by roughing up with emery cloth.

Also needed three motor mount gromments to line it up with the motor shaft. Here is the replacement cartridge, Tetrad TK-7.
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Dave

TC Chris

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Re: Packard Bell RPC-66
« Reply #7 on: December 01, 2017, 08:12:57 PM »
So, the usual question:  how does it sound?

Chris Campbell

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Re: Packard Bell RPC-66
« Reply #8 on: February 14, 2018, 03:07:23 PM »
There is a model tier above this one with a separate amp chassis. RPC-56 in sams 905, which I have been using as the RF-IF-MPX and preamp is identical.

It only gets about 15-20 watts loud, but does not distort at full volume which is unusual. The radio tunes as good as a Zenith, and we have a crowded band that puts it to the test. PB would have made a great car radio based on my observations.

Well, I had some issues pop up in 2 months of regular shake-down testing. I need to fix it for good - just selling it or returning it without testing is inviting trouble, even on an SS model.


1. The FM quit while tuning around one day. The mixer transistor shorted collector to emitter. A generic 2N3904 NPN-Si brought it right back. No idea why it quit like that.

2. The power supply developed a faint hum - resolved by increasing two of the 22 volt supply capacitors from 1000 mf to 2200 mf.

3. My work space is not heated well, so on warmer days the V-M changer worked just great but 2 days ago it made some noises like it was binding and I pulled up the platter. Idler wheel and spindle bearing is OK but the motor barely turns now. Very odd - because I took it apart initially, cleaned and soaked the motor bearings in 3in1 oil. Now I have to do it again or replace the motor, I have a few spares.

4. Both the radio AND record player seem to hiss or lisp (on "s" sounds) as if the tuning is not right on. Its either an amp issue or speaker issue. I was considering replacing both 6 mf non-polar crossover caps. But need to try known good speakers first. I really need a distortion analyzer but Ill try using my audio generator and scope if I need to. Both channels seem to be affected.

5. The first tetrad replacement cartridge had a temporal static pop on the right channel, most noticeable during play of my test record, CBS "seven steps to better listening". Luckily, I had another cart and the issue disappeared.
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Dave

TC Chris

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Re: Packard Bell RPC-66
« Reply #9 on: February 15, 2018, 08:43:31 PM »
Nice write-up.  I usually assume speakers, a mechanical and fairly durable part of the device, are not at fault.  I do have a marine Radio Direction Finder that i use as a music source on my local sailboat (it has an FM band).  My brother gave it to me--got it on a boat he bought.  It would play along just fine and then die after about 5 min.  Turns out the speaker voice coil was opening.  Very odd behavior. 

My only Packard-Bell gear is a ca. 1949/1950 FM tuner, a little 2-gang device of no special value.  It was my college tuner and hard a hard time receiving the "underground" FM station about 30 mi. away.

Chris Campbell

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Re: Packard Bell RPC-66
« Reply #10 on: February 23, 2018, 12:51:42 PM »
I plan to sub-out the crossover caps and tweets but my ears may not be enough to confirm I'm on the right track.

the good news is the record changer just hates anything under 55 degrees, playing fine again during our heat wave (80+ on wed!!) this past week.

I am repairing my audio generator before I put this amp on my dual trace scope to analyze how it behaves at various frequencies. A square wave generator can provide some clues to amp issues as well. A distortion analyzer is on my wish list.
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Dave