[MRCA] Aurora VBP-1

Tue Jan 28 02:15:12 EST 2025

Hi Ray,

Yeah, those Aurora VBP-1s are a really great solution to replace an 
electromechanical vibrator. They are very small (a bit less than 3/4" 
square) and can mount nearly anywhere you want under the chassis. The 
microprocessor onboard is programmed with a dead zone between polarity 
switches which prevents the power trans from getting excessively hot. 
The heating comes from the power tranny being over saturated from the 
current spike generated at same time the next half-cycle current begins 
to flow in typical switching circuit designs using simple logic chips. 
The old product line of SS vibrators from Antique Automobile Supply, for 
example, did not have that brief switching delay which caused the 
transformer run hot in some radio designs. I suspect that design was 
using a simpler switching circuit. The primary current generated from 
the magnetic flux collapse when the polarity is immediately switched in 
the original design would be additive to the current rise which 
immediately appears at start of the next half of the cycle current flow. 
The delay of several hundred nanoseconds or more programmed into the 
code of the Aurora vibrators allows the back EMF to dissipate before the 
rise of the alternate half of the cycle.

Before I had discovered those Aurora SS Vibrators, about 15 years ago I 
had a '65 Thunderbird radio I restored for a customer in the 
Chicago-land area using an Antique Automobile brand SS vibrator. That 
unit's design at that time caused the T-bird radio's tranny to run way 
hotter than I thought was reasonable. I understand the Antique Auto SS 
vibrators have been improved in some manner fairly recently which I 
presume (rather, I hope) may be intended to prevent over-saturation of 
the transformer laminations.

Unfortunately, I cannot obtain a replacement stock of VBP-1s from Aurora 
since I'm not a 'dealer' of theirs. And recent contacts with actual 
dealers result in them reporting they are not allowed to resell Aurora 
SS vibrators to non-dealers like me. And I have been unsuccessful up to 
now in finding absolutely *any* contact info for Aurora. They've got 
their market locked up, it seems. May have to find a way to extort 
contact info from one of their dealers :-)

A SS vibrator supplier I've found several years ago is Peko Radio <PeKo 
Radio <https://www.pekorf.com/Radio>>. They have a line of SS vibs which 
provides us with a more flexible line of alternatives to Aurora albeit 
the PC assembly is much bigger than those Auroras.

See attached picture showing how I mounted the Peko product under 
chassis in a 1941 Ford radio made by Philco (model F-1841) of which I 
had restored for a local dentist. I tend to not cut open original 
vibrator cases to both save time and to prevent "ugliness" of a patched 
together vibrator case, so they get placed under-chassis as shown. The 
Peko RVB-2B I had used worked out very well, no excessive heat at all 
from the transformer or vib board itself. Great! Peko products are a bit 
more expensive than the Antique Automobile SS vibs and even the probable 
current pricing of the Aurora products. Check Peko out using the link I 
gave above.

I disconnect the 6 or 12 volt wiring from the vibrator and use an 
additional small terminal strip if needed. Even with a SS vibrator you 
must replace the buffer capacitor with a new one of the same value to 
ensure the driver MOSFETs are not damaged by voltage spikes generated 
from the secondary flux collapse inducing high current spikes into the 
primary at time of switching. The tranny and cap are 'tuned' to keep the 
spike level as low as possible.

I just need to buy about a half-dozen of those Antique Auto SS vibs and 
see how they perform in various radios. So right now I'm on the fence 
about which to use - Antique Autos or Pekos (Auroras are out now). But 
I'll definitely use the Peko products to restore a few units of my mil 
gear vibrator power supplies since vibrators are used in those pieces 
which do not conform to anything Antique Automobile offers. The Peko 
RVB-2x units will handle up to 30 volts DC supply voltage and are sold 
as positive or negative polarity.

Now that I have recently retired I'll have time to be doing more antique 
auto radio restorations after running some advertising in Hemmings and 
maybe elsewhere. Should make a few extra bucks from that activity to 
feed this old antique and military radio hobby from which I seem to 
suffer :-)

Good luck on your projects, Ray.

Best regards,  Chris F.

On 1/22/2025 2:06 PM, Ray Fantini via MRCA wrote:
>
> I am looking for an Aurora VBP-1 assembly, that a little solid state 
> inverter assembly that replaces vibrator in old radios. The company 
> has several resellers listed on their web site and they don’t list the 
> product, don’t answer the phone and some don’t appear to do anything 
> at all.
>
> Or if anyone knows of anything else that will replace a mechanical 
> vibrator for a positive ground system, please let me know. Want 
> something that fits into the same profile so I can gut the old 
> vibrators and install the VBP-1 inside. Don’t want to have to build up 
> something that I should be able to buy for less.
>
> Ray F/KA3EKH
>
>
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-- 
================================================================
Christian R Fandt
Jamestown, NY 14701
   >  Electrical/Electronic Collector & Historian: Radios, Early Computers, Test Equipment
   >  Radio restorations:  Pre-1970s Automotive & Home radios
   >  Retired engineer/consultant on electrical/electronic contact physics

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