Fusprech.a

[Yuri D.]

Is there a real reason why the Fusprech. series (a, d, f) had different frequency ranges, or were they just different versions of the same device? The reason I ask, is because the Fusprech.a was made in 1940, Fusprech.d in 41, and Fusprech.f in 1942-45.

Yuri

[Yuri D.]

Here is a new Fusprech.a

[Yuri D.]

Pics from some other angles:

[Yuri D.]

The manufacturer's emblem:

[Dufleuve]

Nice early set. I like the Stassfurter logo on it.

[Funksammler]

Is there a real reason why the Fusprech. series (a, d, f) had different frequency ranges, or were they just different versions of the same device? The reason I ask, is because the Fusprech.a was made in 1940, Fusprech.d in 41, and Fusprech.f in 1942-45.

Yuri

They are different versions

Fuspreach. a: 24.11 - 25.01 Mhz; primarily used in "Panzerspaehwagen" (armoured reconaissance vehicles)

Fusprech. d: 23.11 - 24.01 Mhz; primarily used in early self propelled artilley and "Panzerjaeger" like the Marder

Fusprech. f: 19.99 - 21.47 Mhz; primarlly used in "Schuetzenpanzer" armoured personnel carriers and variants.

I assume the b and c versions were originally planned to use the 21 and 22 Mhz slots, but never implemented.

The different frequency bands were used to avoid interference if a lot of vehicles were operating in a small area (typical of the Blitzkrieg tactics). I guess later in the war this was no longer an issue and since a lot of the roles of the earlier vehicles were taken over by variants of the Sd.Kfz 250/251 only one version survived: the Fusprech.f.

regards,

Funksammler

[Yuri D.]

That was good information Funksammler, but what about the surviving Panzerspaehwagen, did they also swich to the "f" after 1942?

Yuri

[Val]

Thanks Funksammler, but was there some specific reason why they went down with frequencies with each new model, instead of going up/higher?

[Funksammler]

That was good information Funksammler, but what about the surviving Panzerspaehwagen, did they also swich to the "f" after 1942?

Yuri

Based on information I can find, the Sd.kfz 234 "Puma" was equipped with a Fuspr. f, so it seems that later manufactured "Panzerspaehwagen" used the f.

I have no information on re-equipping surviving reconaissance vehicles with an "f" but it makes sense that if older vehicles had to operate together with the newer vehicles such as the "Puma", they would update the radio in the older vehicle.

Also the performance of the "f" seems to be slightly better than that of the "a" and "d" versions, this could be due to better antenna performance or to the propagation of the radio waves at the different frequencies or both.

I guess the level of losses meant that in reality it didn't take long for the Fuspr.a and d versions to be "cycled out" of the system so that by 1944 primarily the f version remained in use.

As to the "logic" of the frequency allocation I have no specific information. It has to be remembered that in the 1930's, the use of VHF was rather revolutionary. The general understanding was that VHF frequencies could only be used for "line of sight" communications and had no value for mobile use.

German experiments however showed they could be very useful and in the few years leading up to WW2 sets and VHF frequencies were tested and assigned to different services. These frequency assignments were sometimes changed (for example frequency range of the original tank set Ukw.E.c was split into that of the Ukw.E.e and Ukw.E.h to segregate the Panzers and Stugs radio traffic).

So it is likely that the assignment of the Fuspr frequency bands went through similar trials and changes, leaving us with a rathe "illogical" sequence...

regards,

Funksammler

[Val]

These frequency assignments were sometimes changed (for example frequency range of the original tank set Ukw.E.c was split into that of the Ukw.E.e and Ukw.E.h to segregate the Panzers and Stugs radio traffic).

So it is likely that the assignment of the Fuspr frequency bands went through similar trials and changes, leaving us with a rathe "illogical" sequence...

Hi Funksammler,

Did you mean Ukw.E.a(1) instead of Ukw.E.c ? I now remember reading somwhere that original Ukw.E.a1 range 25-33,3 MHz was changed, because frequency range 25-27 MHz was reserved for sound measurement (Schallmess). Ukw.E.h and Ukw.E.e are just below and above that Schallmess range. Maybe thats play also role in assigning fusprech ranges.

[Hue]

interesting puzzle Also interesting they progressed down in frequency.
That would avoid a lot of other traffic in the low VHF and including U.S.
armor and arty. I wonder if Arthur Bauer has the wisdom on this. I also
note the FuSprech design is inherently limited to a rather narrow band,
as it uses the same oscillator tube for both R and T, just switching
different tuned circuit in. So there's no netting and no nachstimmen.
Not a problem with the wide selectivity; but getting it to track well
over much more than this tuning range, I think would be really
difficult. I was also surprised at the rather short working range specd
for this radio. I cannot recall at this moment whether it has an RF
stage or right into the mixer. Oh, BTW, another logic puzzle: why would
they have a special headset, just for this radio?? That's hardly
Gleichschaltung! -Hue

[Yuri D.]

Welcome to the forum Hue!

All good observations.

Yuri

[Val]

Hi Hue,

Yes, that headset issue is interesting, we wondered about it in another theme.

About allocation frequencies, at least until october 1944 (i have table at that date), germans have strict division of frequencies whether the communication was HQ, batallion, division, artillery, tanks etc. based. As germans have ordnung in everywhere, i believe there was reason for different Fusprech frequencies.

[Funksammler]

The Fuspr.a used the Dfh.d, the same low impendance type that was used in early Panzer intercom systems. We had a discussion on these earlier: http://dev.wehrmacht-awards.com/foru...d.php?t=491718

The other Fuspr versions used the Dfh.b., I guess they were developed slightly later when the Dfh.b became the standard.

Primarily the Funksprechers were used with the loudspeaker.

regards,

Funksammler

[Yuri D.]

interesting puzzle Also interesting they progressed down in frequency.
That would avoid a lot of other traffic in the low VHF and including U.S.
armor and arty. I wonder if Arthur Bauer has the wisdom on this. I also
note the FuSprech design is inherently limited to a rather narrow band,
as it uses the same oscillator tube for both R and T, just switching
different tuned circuit in. So there's no netting and no nachstimmen.
Not a problem with the wide selectivity; but getting it to track well
over much more than this tuning range, I think would be really
difficult. I was also surprised at the rather short working range specd
for this radio. I cannot recall at this moment whether it has an RF
stage or right into the mixer. Oh, BTW, another logic puzzle: why would
they have a special headset, just for this radio?? That's hardly
Gleichschaltung! -Hue

No HF stage - went straight into mixer.