Marine radio

[Radio Fixer]

http://www.ebay.co.uk/itm/Marconi-Marine-Valve-Radio-Receiver-NS-702-Atalanta-/291146860371?pt=UK_Collectables_RadioTelevision_Telephony_SM&hash=item43c9b48753

Looks in good condition. Bet Lawrence knows the model. Might even get that one past SWMBO onto the sideboard if built into a posh box ?

And then there is this ... I have an article on one of these Colins, construction is simply amazing. The top of valve electronics.

http://www.ebay.co.uk/itm/COLLINS-51J-4-tube-shortwave-ham-receiver-militairy-rohren-valve-radio-empfanger-/251528596085?pt=Radio_TV_Musik&hash=item3a9045ca75

Gary

[pwdrive]

One of those came up for grabs not far from me a couple of years ago but it was a bit damaged and various chunks were missing so I declined, the one in Gary's link looks to be in good condition so far as I can see, they do come up on Ebay but not very often.

It has a single balanced demodulator for CW but that should also work for SSB reception quite well, any AM can be nulled out, a while back I found an explanation for that demodulator in PDF format, I posted it on the forum when I found it, here it is:

http://golbornevintageradio.co.uk/forum/showthread.php?tid=3321&highlight=balanced+demodulator

I built a single balanced demodulator using an EB91 in a direct conversion receiver I knocked up many years ago with a home brew trifler wound coil, worked quite well as I remember, it nulled out most of any AM breakthrough quite effectively.

Lawrence.

[pwdrive]

Here's one for you Gary, a 5t:

http://www.ebay.co.uk/itm/National-HRO-5T-Communications-Receiver-12-plug-in-coils-WWII-WW2-Ham-Radio-/111359913947?pt=UK_Collectables_Militaria_LE&hash=item19ed916fdb

I have one of these complete with 12 general coverage plug in coil packs in the same type of box as the one shown in the above listing, for finer tuning of the amature bands the bandspread coil packs are required, there are 4 of them, they cover most of the SW bands they have a frequency graph in both windows, the general coverage ones only have a frequency graph in the left hand window, the other window is for pencil logging, the bandspread coil packs can be set as for general coverage or bandspread on the amature bands by altering the screw positions on the underside of the coil pack (easy to do)

Mine, although working, has been modified in the past to more modern minature valves for the Osc/RF etc and a HT stabilizer valve has also been fitted, who ever did it did a good neat job, no drilling or hacking, my other one is an HRO Senior, that's the one with the plug in Xtal filter on top of the phasing unit, on the later HRO's a much smaller Xtal is used and is hard wired inside the phasing unit as is the case with the 5t, the 5t in the listing is most probably tropicalized.

Lawrence.

[Radio Fixer]

I hadn't noticed you had added to this post Lawrence.

Here's an article on the HRO by Peter Lankshear printed in "Discovering Vintage Radio", AUS, back in the 70's.


  img248.pdf (Size: 2.18 MB / Downloads: 90)

It may be of interest to a few

Gary