[MRCA] BA-48 Rebuild Powering GRC-109

[Ray Fantini]

Been doing a lot of battery packs for radios the last couple years. Way less issues then inverters. Battery drain for most tube receivers that were designed as tube receivers is very low so ten nine volts cells in series preforms well. The only thing I do different is to use battery top clips because snaping them together may be prone to coming apart during transport.
You can buy a twenty pack of clips on the Bay for under ten bucks!  If you want can send you some.
Attached is a picture of a pack that I did for a BC-474 that I think is a BA-84 that was used in a bunch of sets.
I used a aluminum plate being they are easy to bend. Like to come acrost the old dead packs for harvesting the connector. Although the filament drain can be heavy on a signal D cell somehow feel that being threes radios sit around for a long time without use that maybe the idea of dry cells in parallel may be a bad idea due to one trying to charge the other when your not watching.
And on the subject of the angry nine don’t forget to do your bias cell in the receiver, chopping up a nine volt battery will provide small cells suitable for replacement. Have a video of that up at:

https://www.youtube.com/watch?v=ekwSnH5sfbw

Ray F/KA3EKH

From: mrca-bounces at mailman.qth.net <mrca-bounces at mailman.qth.net> On Behalf Of MilComm Guy
Sent: Thursday, October 23, 2025 1:37 PM
To: mrca at mailman.qth.net
Subject: [MRCA] BA-48 Rebuild Powering GRC-109


With all the needed items on hand today I rebuilt the BA-48 battery to power the GRC-109 receiver and eventually the GRC-9 receiver, still looking for a CD-1119 cable for the GRC-9.
  This is probably the simplest way to do it using minimum soldering and purchased materials.  The 9V batteries simply snap together, no holders or extra wiring, two D cells in parallel using a holder that snaps together and some hot glue and cardboard.  I made an insert from cardboard to hold the batteries, there is extra space so you can add an additional 9v pack to double the capacity.  The size of the BA-48 is a perfect match to re-stuff with commercial batteries.
Cardboard Insert
[cid:image001.jpg at 01DC4423.AD4B4E50]
Battery layout
[cid:image002.jpg at 01DC4423.AD4B4E50]
Batteries/insert installed
[cid:image003.jpg at 01DC4423.AD4B4E50]
Final product powering GRC-109 receiver
[cid:image004.jpg at 01DC4423.AD4B4E50]

73
Mark
K1HF
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