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CRT One Portapak

Joined: September 29th, 2017, 8:33 am

September 5th, 2018, 12:40 pm #1

I absolutely loved my old Portapak back in the day. I have been waiting for one to pop up on eBay for the right price, but I am really loathed to be spending decent money on a 30 year old radio. I just think its a minefield to take a gamble on something that old and not expect problems.

...And then, even if I do get a decent one, its still limited to 27/81.

I am now pondering building myself virtually the same thing out of a CRT One, the parts list would be simple

The Radio (<£50)
1 x 10xAA Battery tray (£1-2 on Ebay)
1 x PL259 to female BNC 90 degree (£1-2 Ebay)
1 x Generic BNC long handheld antenna of choice (£20 ish)
This would suffice to operate it laying flat on a surface with the antenna at 90 degrees to the radio. but I'd buy an additional 90 degree bnc adaptor to sent the antenna across the top of the radio, so it could be used as a conventional handheld.

The only thing not accounted for here is the case to hold it all together, My wife is a seamstress ;)


I feel this would give me, a Brand new Portapak, with better channel capability, for about £75, with admittedly the weak link being the antenna, but then there is always the option to plug in something decent if required.

What do you think? I very much doubt I am the first Portapak fan to come up with this idea so would be great to hear if someone else has tried this.
Last edited by Doctor Z on September 5th, 2018, 12:59 pm, edited 1 time in total.
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Joined: August 24th, 2014, 5:33 pm

September 6th, 2018, 4:56 pm #2

go for it, had a crt one was a powerfull little radio. one issue tho they do run quite hot because of size so would prob need to take it out case for operating
M0LSG
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Joined: April 23rd, 2011, 5:12 pm

September 7th, 2018, 9:45 am #3

razor36 wrote:go for it, had a crt one was a powerfull little radio. one issue tho they do run quite hot because of size so would prob need to take it out case for operating
I would consider a better choice of power plant. For example a pack of TR 14500 Li Ion (AA size) batteries each rated at 3.7 volts and upwards of 2500mAh each will be lighter and so much more efficient than AA rechargeables and less than half the weight per V. I use these almost exclusively to drive large model locomotives and as portable plug in packs to run a 14W portable transceiver. Use a rigid briefcase for the kit with an ally sheet inside the lid with a screw mount which will actually take a sirio mobile antenna of choice if appropriate.
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Joined: December 17th, 2015, 6:56 pm

September 7th, 2018, 7:37 pm #4

Roy2812 wrote:
razor36 wrote:go for it, had a crt one was a powerfull little radio. one issue tho they do run quite hot because of size so would prob need to take it out case for operating
I would consider a better choice of power plant. For example a pack of TR 14500 Li Ion (AA size) batteries each rated at 3.7 volts and upwards of 2500mAh each will be lighter and so much more efficient than AA rechargeables and less than half the weight per V. I use these almost exclusively to drive large model locomotives and as portable plug in packs to run a 14W portable transceiver. Use a rigid briefcase for the kit with an ally sheet inside the lid with a screw mount which will actually take a sirio mobile antenna of choice if appropriate.
Interested in knowing how you use them Roy, 3 x 4.2V fully charged gives you not a lot of run time of useful voltage and 4 x 4.2 volt is too much for most if not all radios.
CT1938 / FOX INDIA 420
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Joined: September 29th, 2017, 8:33 am

September 9th, 2018, 10:26 am #5

Thanks for the replies, we'll see how things go, I chose the Nimh route as I already have the batteries and chargers, it would be easy enough to carry a spare set if necessary, and as a last resort there is always the Alkaline option,  I have enough of the damn things that I can have a set on charge, a set ready, and a set in the radio at any one time. 

I am having some thoughts about SWR though, I assume handhelds must have some kind of circuit to deal with poorly matched antennas and random levels of "counterpoise", that a standard rig like the CRT would not have.  I think running a swr meter inline would kind of kill the simplicity of the unit really. 
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Joined: January 29th, 2011, 12:28 pm

September 14th, 2018, 6:06 pm #6

AA batteries are a waste of time you need a SLAB to use on the radio due to the power output of 4 watts.
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