[Premium-Rx] WJ-8711A or WJ-8712P

[Steve Pappin]

I have been fielding a lot of questions about the WJ-8711A. People want to buy them, have them repaired, upgraded, or sell them. I will probably get blasted for this putting this information out but here goes. The 8711A was designed as a low cost receiver and it is often not cost effective to repair. The evolution of the 8712 and 8711 saw many refinements. Most of the updates for the 8711A were implemented to deal with significant performance issues. In the end only the 8712 survived because it was the only clean sheet version that performed entirely as intended. WJ released the 8712P to replace the 8711A.

The 8712P is a clean sheet version of the 8711A that does not have the problems. It meets MIL-STD-461 when installed in a metal chassis.The 8711 was an after thought. When the 8712A first came out there was a small requirement for units with a front panel. WJ very quickly spun up the low cost 8711 and it had a lot of problems. It was never meant to go into high volume production. WJ finally redesigned the 8711A as the 8712P. The 8712P is everything that the 8711A was supposed to be. It is a solid and serious HF receiver that meets the stringent requirements of MIL-STD-461 when properly installed. It is basically the new 8712A with a robust front panel.

I can offer the 8712P with options. Take a look at the 8712A data sheet which lists all the options. The only significant difference between the two is that the 8712P has a front panel. Options include a pre-selector, rack mounts, and more. 

I will still support the 8711A on a limited basis, but it is becoming harder and very expensive to provide new parts. A new front panel sells for $4000.00. DRS is reluctant to respond to requests. They would like to see the 8711A go away. The design has many weaknesses: front panel switches, encoders, power supply, radiated noise, too many firmware versions, etc. The 8711A was their VW. It was designed as a very low cost receiver for COTS applications, and thus the HF-1000. It was design to last for 10 years maximum.

What about the 8711A? If you can find one that is new or one that has low mileage they are a good deal. The final versions have plastic encoder shafts that do not radiate. The switches are still the same low cost ITT-Schadow carbon types which are not serviceable. The switching power supplies last for about 10 years. The final build of 8711A's rolled off the assembly line last month and went to a government contractor. There will be no more. New parts are available but they are very expensive.

My opinion: The 8711A is a great receiver if it is a later version, has low mileage, and has been treated well. They are not easy to repair. New hard parts and assemblies are very expensive. Firmware upgrades are not compatible across all radios and in some cases will render the radio unusable.

I'm currently working with an agency that is replacing their 8711A's. The failure rate jumped to a very high level right at the 10 year mark. 

Best Regards,
Stephen Pappin

PCS Associates
5621 Palmer Way Suite A
Carlsbad, CA. 92010 USA
Phone: +1-760-487-8951


Online: http://www.pcs-associates.com